Problems with Municipal Street Tree Code

First off, a slightly late Merry Christmas to all! We hope no one’s grandma got run over by a reindeer this year.

Well with the holidays more or less behind us, I’m certain we must all have our mind on just one thing, which of course is street trees. Is there anything more enchanting than the silhouette of bare winter branches against a dark, rain-soaked sky? Come to think of it, perhaps there is.

I’m going to dive into what I think is wrong with municipal street tree code, and in so doing I’m sure this is going to sound like another one of those really negative posts. Am I just here to pick on municipalities for creating policy on this stuff? If we’re doing things so wrong, then what are my suggestions for positive change? Well, with the publication of this blog post comes my commitment to follow it up with something productive. That may take me a few weeks but we’ll get there.

Let’s start with an example of why I think this is necessary. Coincidentally, Lance Wright recently posted the following commentary, with photos, to Facebook:

“Portland has been planting Parrotia persica frequently as a street tree, probably the cultivar ’Vanessa’. The species is ‘decurrent’, with weak apical dominance, as it has a shrubby form with competing leaders. Often times these tend to sucker and sprout, even without pruning or damage, as does the tree pictured here forming a very congested silhouette down to the ground. These can also be quite broad relative to their height…making them a questionable choice for narrow parking strips such as this. As street trees are rarely pruned /trained this is what you can get. This one has been in place less than five years and is already encroaching into the street and taking over the sidewalk. Some Parrotia are better behaved, but I often see this in SE Portland. I do love these in the right place…I have a 30+ year old one in our garden!”


Photos by Lance Wright


So I’m just putting that out there as an example to introduce the topic. It is apparent that something has gone wrong in this instance, because the result is less than desirable. It is worth exploring what that might be.

Rather than Portland, however, my frame of reference here will be the Street Tree Guide for the City of Port Angeles, since it is the city closest to our nursery that has any kind of street tree code. This document is available online here.  (Parrotia is on their list as well! By the way, if any such document exists for Sequim, it is not online that I can find. Let us hope this means it is not too late to craft a more sensible policy!)

I want to begin by saying that I don’t think there is anything wrong with just having guidelines in general that concern street trees. One has to start somewhere, and something is better than nothing. No city, nor its residents, want street trees to rip up sidewalks, drop heavy cones on cars, or otherwise become a public hazard. I can also say this policy is not in any way consistently enforced, as one can tell just by looking around the city. Whether we think a high level of enforcement is good or bad, I would put forth that a city should have the goal of drawing up a plan that allows for easy and consistent enforcement with a minimum of ambiguity or exceptions. That way no one feels like they are being treated unfairly.

Unfortunately, however, a quick look at this document reveals some inconsistencies, which I will describe. One also finds quite a few errors of spelling, word spacing, underlining and layout that make it look a bit sloppy and unprofessional. I’m not saying I’m always perfect in that regard myself, but it jumps out at me. (I’d be glad to fix that!)


(Click images to enlarge)

I’ll skip over the first page, which I don’t consider to be the most controversial or problematic part of this document. Moving on to the second page, we have a set of guidelines which mostly make good sense and are fine, until we come to the part about minimum caliper requirements. After some consideration I’ve concluded that these requirements are a big part of the problem. Having looked into this topic a bit, I’m wondering if there’s something I’m missing, because the reasons I’ve unearthed so far for establishing minimum caliper requirements just aren’t great. Generally they seem to have more to do with project bids by landscaping firms, rather than individual homeowners: municipalities don’t want landscapers cutting corners on tree size to reduce their costs and appear more competitive. There is also the issue of tree replacement: if a large tree is lost there may be a perceived need to replace it with something immediately substantial. (Even this is debatable, as I hope to demonstrate later.)

The main problem with caliper standards is that they are far too limiting for everyday homeowners or gardeners. The homeowner is going to have a lot more tree options if not restricted to what is available in a large caliper. Also, if they are paying for the trees themselves, this could be the difference between buying a tree vs. not buying it at all, if they are on a tight budget. In my view the homeowner should be automatically exempted from this requirement except perhaps in instances where they are responsible for the loss of a large tree that is being replaced. There are other reasons why cities should be much more open minded about this as well, but I’ll get to that in the follow-up post.




So here we have the list of recommended large and medium trees for Port Angeles. First of all I notice that at least half of these trees are going to be difficult to find in any size. Suppose we classify trees three different ways: those recommended by municipal tree code of Northwest cities, those available in our local nurseries, and those that are actually the best performers in our region. We would have three very different lists, with some overlap, but a lot less than you might think. This discrepancy is unfortunate but there it is. For example, not once ever in my life have I seen Osage Orange in a nursery around here; it is exceptionally rare in the Northwest.

Then I notice that some of the medium trees grow larger than some of the large trees. So that’s interesting. In general some of the heights seem a bit “off” for what may be expected in our climate. But then others are accurate enough. This leads me to think parts of this list were assembled from a city or cities in a different climate, as some trees grow to a smaller or larger ultimate size in our climate than described by many popular references. A good regionally specific reference as to what ultimate sizes for trees we can truly expect in our climate is found in Trees of Seattle, by Arthur Lee Jacobson (2006). The reader will find some major surprises as to how certain tree species (commonly sold, and otherwise) have performed in the Northwest over time. However, even in that book, some gaps exist for species that haven’t been established in our region for very long.



I find it interesting that small trees are not preferable. This may be because they don’t cast as much shade or contribute as much canopy for wildlife habitat or sequestration of pollutants. There may be other reasons I haven’t thought of. I think we ought to regard this principle with a great deal of flexibility, as the homeowner may wish to use the space for something besides grass and one huge tree that shades out everything around it.

In general the selection here doesn’t excite me too much. The first thing I would take off the list of small trees is Prunus virginiana. It is ugly and suckers everywhere: I know this because I have been trying to eliminate it from our property for years. I would also note that Acer davidii (never have I seen this in a large caliper, BTW) certainly looks far better in about half shade than in full sun. Ideally a street tree should be adapted to mostly sunny and relatively dry conditions; species should be selected with this in mind.

So taking those lists together, here are the main things that stand out. I know it’s kind of buried down here, but the following issues are really the central point of this post:

1. All the recommended trees are deciduous.

2. The majority of these trees are native to climates where it rains all summer.

So to the first point, although I don’t automatically hate all deciduous trees, I am an advocate of using broad-leaf evergreens far more than we do around here. Some have been accused of looking “gloomy” in our winters, but for the most part I think they add interest by giving you something to look at in winter besides bare sticks. Many of them have interesting foliage, form, or bark that is very appealing when the winter sun hits it. There are literally hundreds of options for broadleaf evergreen trees that do well in the Northwest; many of which you can read about in books such as Trees for All Seasons. Even if you are not a huge fan of broadleaf evergreens, there can be no sensible reason why ALL the trees on the list need to be deciduous.

But I am sure this all comes back to the caliper requirement. Broadleaf evergreens are generally grown in containers, rather than produced in the field, and are thus seldom available in the large caliper desired. Put another way, because they are container-grown rather than field-grown, they are more expensive to produce to get the same size as a comparable deciduous tree, and thus are not produced because of the lack of demand for the more expensive option. Doubtless this is a major reason they have been largely overlooked.

Now to the second issue. I am aware that some planting areas are irrigated (at least until the irrigation system breaks), and there is a certain amount we can get away with as far as using trees native to climates with more rainfall during the growing season. In the follow-up post I will discuss what I believe makes the most sense as far as selecting and planting species that are well adapted to our region. But, taken together, tree species native to China, Japan, and the Eastern United States, all places where it rains all summer, make less sense here than species better adapted to dry summers. As my readers are well aware, we have a dry-summer climate here in the Northwest. Thus, I simply don’t think it makes sense to recommend continued planting of thirsty trees. It makes even less sense when we consider that our summers have been on a warming trend and water resources are likely to be increasingly strained over time.

Still, I’m not drawing too hard of a line: some tree species from wet-summer climates perform adequately here, and examples of them can be seen in cities all over the Northwest. Some perform well in Port Angeles but not Portland, since Portland is that much hotter and drier. Some of them perform well but only on good soil: in less than ideal soil conditions they languish and die. For example, Cercidiphyllum japonicum, a relatively popular/available selection from the list, really needs heavily amended or deep, fertile soil to do well here without irrigation in the long run. One could recommended it for, say, Mount Vernon, a city built on deep, alluvial soil. But for much of the Northwest this species isn’t a great choice.


Here is where more problems and inconsistencies pop up. But before getting into that I would say there are large parts of this list I certainly agree with. Many of these trees are inappropriate as street trees and ought not to be used, no doubt about it!

“Large Evergreens” – I can see why something like a 200′ tall douglas fir doesn’t make sense as a street tree. Still, I would think you’d want to allow for quite a few exceptions to this rule, especially for those species which develop dome-shaped canopies, have exceptional drought tolerance, and/or remain compact in stature. I can’t believe they forgot to mention Leyland cypress, the scourge of the Northwest. Also I find it interesting that deciduous conifers and true cypresses are not mentioned here; though obviously they are also not on the approved list. There are a few rather large Monterrey cypresses around Port Angeles, which are on the large side for a street tree but make quite a statement!

The next six things on there are certainly problem trees. However, I would question whether Platanus occidentalis is really so much better behaved than P. x acerifolia, which is on the approved list. My impression is that all Platanus have rather aggressive root systems, but perhaps there is some variation.

Then you get to “palm trees.” This is the part that tells me some snippets of this document were pulled from a completely different climate. I would like to know where in the Pacific Northwest anyone has seen palm trees cause the problems this document accuses them of: invasive root systems, damaging sidewalks, weak wood that breaks easily. In California, larger species of palm trees have moderately aggressive root systems but even these don’t have the capacity to crack sidewalks. Palm trees don’t even form a woody root system. Most problems with palms are associated with species that won’t even grow long-term in our climate (Washingtonia and Phoenix species, mainly). These problems include being messy, harboring rodents, dropping huge leaves and sticky fruit at random, and being a major fire hazard when the older leaves aren’t trimmed off. But none of these issues were mentioned in our document, so I’m just saying let’s be honest about what those problems are.

Most importantly, because we cannot grow those problematic species of palms in our climate, all the concerns about them that I described don’t mean much here in the Northwest. Our most popular hardy palm, Trachycarpus fortunei, is quite well behaved, has never been known to harbor rodents, possesses fruits that are small and not messy, and I’m darned if I’ve ever heard of one catching fire.

Now as far as using T. fortunei as a street tree in our climate, I think that it is too small-scale to be impressive, besides which it prefers summer water. There are some nice ones in Port Angeles (including some right along Eunice St. as street trees) but they can also look a bit weather-beaten with exposure. So to clarify, I’m not advocating its use as a street tree; I mainly want this document to make sense from a horticultural standpoint.

(Now Jubaea chilensis as a street tree, I could get behind! The Seattle Arboretum invested in some large ones a few years back, which so far has paid off as they are looking great [except for people stealing the fronds for Palm Sunday]. It has also proven hardy in Victoria. Notably, this species is native to a summer-dry climate. Of course, one may still complain about the fact that it may take decades for enough clear trunk to be produced that the fronds are above head height.)

So moving on from palm trees, I have no problems with the next bit, although I will say I have noticed quite a few of these being used as street trees in Port Angeles. I find it interesting that Fraxinus are prohibited generally; certain ash cultivars have been very popular street trees in other municipalities, especially in the interior West, and remain so even now with new plantings continuing. Three specific ashes are mentioned and it’s ambiguous as to whether the widely used types should be allowed. Also, as long as we’re considering birch, we may as well ban them all equally since they are all aggressive surface rooters that are greedy for water and can get significant pest problems when they get too dry (though I’ve seen less of this in Clallam County than in, say, Seattle or Olympia, no doubt because summers are cooler).

Moving on to horsechestnut—wait, didn’t we just see that on the recommended trees list? And it’s certainly more LARGE than medium. Also it reseeds itself. It does great here and is very well adapted, but if we are concerned about reseeding potential, we probably don’t want to recommend it.

Fruit bearing trees—mixed feelings here, since there is something to be said for planting fruit trees in publicly accessible places. However the problems with them are substantial: dropping fruit on cars, staining sidewalks, etc. There would need to be some assurance that they will be pruned annually and maintained to fit the space. I don’t expect that to be realistic in most instances.


Overplanted trees: YES! I’m on board with not using any more of these. But let’s add to the list virtually anything else native to a climate with wet summers that is reasonably common—perhaps granting exceptions for a few tough species that still do pretty well here (eastern US oaks, for example). As long as we’re telling people what not to plant, we might as well be consistent!

Ok, that is enough with the critical mindset for now. In a future installment, I promise to offer constructive thoughts on the topic in general, on what types of trees should be used, and will be so bold as to recommend at least a starter selection of appropriate species that would make great street trees in the Northwest.

New Low Impact Garden in Sequim

Before I get to the subject at hand, allow me to interject a brief commercial announcement. This Saturday we will be at the Fronderosa Frolic in Gold Bar with lots of other exciting nurseries! As usual, your special requests are welcome. Please note the event is only ONE DAY this year. This might be the region’s geekiest plant sale. Maybe we will get some thunderstorms. That would be exciting. See you there! Woohoo! And such. OK, moving along now. . .

I recently learned of this new “low impact” garden that has been installed at Sequim’s Carrie Blake Park (here and here). So I thought I had better go check it out and see what I think, since “low impact” and “water wise” are pretty much what we are about (along with excellent plantsmanship) here at the Desert Northwest.



I ought to preface this post by noting that I had no idea any of this was going on until I read about it in the Sequim Gazette online. Some of our local nurseries donated plants to this project, but we were not contacted. I suppose that means there are a lot of people here in the area who still don’t know about our nursery. Well, we are not in a prominently visible location, which you will know if you have been here.


The garden area is divided into several different sections, which I didn’t figure out until the end since I started at the “wrong” end of the garden and missed the interpretive sign. The larger part of the area consists of “open prairie” and “woodland” plantings. There are also demonstration rain gardens, seashore gardens and a rock garden.

I am glad they have the rock garden. Rock gardening is kind of a big deal when it comes to combining low-maintenance with plantsmanship. It is tempting to think of rock gardening as a dying fad for eccentric old geezers, as I (dare I admit) once did. I have been slow to get into it because of the amount of time and skill it takes to place the rocks. But there is certainly a such thing as a garden that combines the best of rock gardening and low maintenance.




This rock garden was small but had a decent selection of plants. It will be interesting to see how the Agaves (A. montana and A. ‘Blue Glow’) do. It is great that someone thought to try them, but I would have started with A. parryi, and I would have started with at least a 2-gallon plant or nothing at all, since smaller sizes just don’t always make it through their first winter. But hey – maybe we’ll get lucky with these; you never know. The manzanita at the corner of the garden (left side of pic above) was not labeled as to species, but looks like probably a form of A. densiflora which means it will get way too big for the space, and grow into the parking lot and halfway over the rock garden if it is not cut back or eventually removed. Oh well.

I thought the rain garden was well done given the limitations of the space. I only wonder if enough water will run into there to sustain the plants that are supposed to benefit from the runoff. Time will tell, I guess.


It is hard to say how the rest of the garden will look until it fills out, so I guess I won’t say much yet. Most of these plants are very small, and one gets the feeling that availability of source material was a major limitation when doing this project. That doesn’t surprise me. Conventional nurseries in our region continue to be pretty out of touch when it comes to offering plants that really like to live in our climate without getting irrigated all summer.


A Madrona. Well that’s good.


One can hardly go wrong with beach strawberry. As long as you keep it out of the rock garden!


Calocedrus is another good choice. This one looks a bit stressed out, but ought to make it.


Lots of kinnikkinnik here. One has to be cautious with it in our climate, I think, because of the prevailing availability of inferior clones like ‘Massachusetts’ that can burn in hotter gardens and aren’t as tough as people expect. ‘Point Reyes’ is probably the best selection for Northwest dry gardens.

Conceptually, I like this garden: it is something I can get behind. The different areas are well thought out. The careful planning, consideration and work that went into it is very much evident. The billboards are loaded with good information and even talk about how dry it is in the Olympic rainshadow.


Here, we have a hose bib. Leading to. . .


. . .a sprinkler. Oh well. It would be better to hand-water the plants to get them to grow deep root systems, but it is probably too many plants for that to be realistic. You can do it with a sprinkler too as long as it only comes on once every week or two.

To me the weakest link is simply plant material. I can’t imagine the full spectrum of plants that was desired was incorporated here (if it was, I have a lot more educating to do about drought tolerant plants for our climate. HINT: very few of them are available at most nurseries). I don’t know what their plant budget was, and it sounds like many items were donated; but my approach would have been to specify what plants were needed beforehand and have someone contract-grow most of them (as my first budget priority), excepting a few things that are readily available. I imagine a low impact garden in the Northwest being full of Callistemons, Grevilleas, Leptospermums, Olearias, a vast array of species Penstemons, Artemisias, Garrya, Baccharis, Yuccas, ice plants, other hardy cacti and succulents, and many more kinds of Cistus, Ceanothus and manzanita; to start with.


A Cistus. It’s doing splendidly – so why just two of them in the whole project?

I (cautiously) mention budget priorities in relation to plant selection because I think it is important to “wow” people before they are interested enough in a project like this to want to be informed about it through brochures, signage, etc. A lot of people aren’t going to be motivated to try something different if they aren’t immediately impressed. I guess I just don’t want anyone to get the idea that low impact gardens are boring or visually underwhelming. I don’t want anyone to feel like a compromise is involved when aiming to conserve water in your garden. There are thousands of drought tolerant plants out there that are suited to our climate, and a water-wise garden can look like a lot of different things.

If, on the other hand, the goal of this project was to get people to use plants that are already easy to find in the nursery trade, then we have a bigger problem: nurseries, largely, aren’t growing the right plants for our region. This sounds like a fine topic for another blog post. And I am now sounding like a broken record.

I hope this review has come off as well balanced and not too scathing. I get it that these plants are not easy to find: it can be a major challenge, but not impossible. I also get it that funding was limited.

So with all that in mind, I wish to let anyone who reads this know that I am happy to contribute plants to this project, or similar projects in the future, especially if they are close to home here in Sequim. That includes both donations (subject to current availability and within reasonable limits) and competitively priced contract growing for specialty items. I’m here. But you still have to find my web site and blog: I just don’t want to seem like a pushy sort of person, I guess.

The Unrealized Allure of Northwest Native Plants

I feel like I mentioned this previously, but earlier this year I heard a well-known speaker (not Richard Hartlage or anybody) give a presentation in which he described the set of Northwest native plants that are useful in gardens/landscapes as “all eight of them.” It is clear that there is much more work to be done… no, that I have much more work to do, to educate people about the vast array of native plants that are, in fact, valuable garden subjects, and not boring. So to wrap up this series on native plants (for now anyways – at least until I write something else about them) I present this third and (if we’re lucky) final installment on the subject, to try to convince you that native plants are, in fact, exciting. Think of it like the third movie in a trilogy: as such, we can only hope that the second post ended disappointingly enough to make this one look good.

To start with, some of you might be wondering by now, what’s a dryland plant? Is that different from a native plant? Had I been giving myself a little more time to proofread and edit these posts for clarity, I would have been more careful to define terms first. Oh well, better late than never.

Furthermore, it may have sounded like I contradicted myself by stating (essentially) most native plants like shade, “and thus make poor choices for urban gardens” and then going on to allude to all these exciting native plants that are out there that people “should be growing.” Huh? – am I making sense at all? What are all these supposedly great plants that are out there; and if they’re so great, why don’t we know about them already? This post is to clear up some of these questions, and to hopefully get gardeners a little more excited about some of our lesser-known native species.

So, here is the deal with native plants, and dryland plants. It is easy to look at an undisturbed native forest and be overawed at the grandeur of giant trees. We think, wow, here nature is at its climax! – and rightly so. Where it is easy to go wrong is when we conclude that this “climax” supports the widest possible selection of native species. We often have a seemingly inherent tendency to associate lushness with diversity. Perhaps that is because we have all been taught that the amazon rainforest contains tens of thousands of species per acre, or something. Which may be true, but things are different in the tropics.

In reality, in the Pacific Northwest, as well as many other temperate regions of the world (one might make an exception for China, but I have never been there), a mature native forest supports only a relatively limited number of plant species. They represent a climax of successional maturity, but not of diversity. To find the greatest diversity of plants, you have to look elsewhere than our lowland forests. Plant diversity increases as you go up in altitude (exposed subalpine and alpine areas), and east (rainshadows and deserts), as well as south. Basically, the more trees you leave behind, the more room you have for a diverse range of sun-loving dryland species. That is why it is easily possible to “get out in nature” in western Washington and not see much of horticultural interest, until you venture away from the lowlands.

So, if we’re looking for interesting native plants to add to our gardens, we need to look up (alpine natives) and east (dryland natives). Now some of you might be thinking, “But I don’t want a rock garden!” (I can’t imagine why not, but we won’t go there for now.) Ok, so skip the alpines, and just go with dryland natives. There are still hundreds from which to choose (well, potentially, if nurseries start growing them).

Dryland native plants are those that occur in the open forests and deserts on the east slope of the Cascade range and beyond, and in a few localized drier places on the west side, especially within the Olympic Rainshadow. That means west of the Cascades, these plants are not common in the wild, nor are they as diverse as on the east side. The important thing characterizing all of them is their ability to tolerate sun, and our period of summer drought. (More broadly, dryland plants can those be from anywhere in the world that occur in similar dry open forests, deserts, or scrub: think of the Mediterranean region, for example. But that goes beyond the topic of this post.)

Now fortunately for us, urban gardens offer the perfect situation for many dryland plants (native or otherwise). Sometimes older neighborhoods are heavily treed; but many are not: there are large areas of the city with plenty of sun. It is in the city that rockeries to provide drainage, walls to reflect heat, and pavement abound. Also, water tends to be expensive: why plant stuff that is going to need a lot of water for its whole life? Dryland plants and urban gardens really are a match made in heaven, if not in a “hell strip.”

What kind of plants am I talking about? Well, when was the last time you saw a Ribes aureum or Artemisia tridentata in a Seattle garden? How about never? Because when you go to a nursery specializing in native plants, they mostly sell the usual limited palette of boring, lowland forest plants, and maybe a few of the easiest and most common alpines (Potentilla fruticosa, Artemisia ludoviciana). This, I suppose, is largely from a lack of awareness that so many other great native plants exist; and to the extent that nurseries are aware of them, they haven’t figured out how to grow them yet, and/or recognized the potential market for such plants.

So, what to do if you want to learn more about these plants? We Northwesterners seem to be somewhat lacking in resources for people interested in exploring and growing our native plants. There are some field guides available of varying quality, and there may be some books about our native alpines or other web sites devoted to this topic that I am not aware of. (Let me know, please!) The only really noteworthy reference I know of specifically dedicated to the cultivation of Northwest Native Plants is Arthur Kruckeberg’s Gardening with Native Plants of the Pacific Northwest. Now before continuing on to discuss a couple of books, I must firmly establish that these are, in fact, excellent and very valuable works, authored by true experts in their field. It’s going to sound like I’m complaining about their shortcomings with nothing positive to say. That is not the case at all: I simply wish to make a point that there is a lot about these plants that we don’t know. The dilemma is, how can a noted author or expert speak with authority on a topic when the knowledge isn’t available in the first place? How do we know whether or not Krascheninnikovia lanata thrives in a sunny Seattle garden until someone has tried it?

So in Kruckeberg’s book, numerous dryland natives are mentioned, but with a lot of talk of “this is really happier east of the Cascades” as if we don’t dare try to grow them on the west side. I cannot help but wonder how many of these have actually been attempted west of the Cascades in the kind of conditions they prefer (i.e. sun, and no summer water once established). The much shorter commentary on these compared to well-known forest natives leads me to suspect that some of these plants may have been attempted once without success and then given up on, or not tried at all. I don’t really know that for a fact, and I may well be entirely wrong; but I do note that some of the comments in this book do not agree with my personal experience. Penstemons, for example, are accused of being “spectacular” but also “short-lived.” “Short-lived” has not been the case for me: they lived for years and years, even when I grew them in rainy Olympia, on heavy clay soil. (Heck, they’re probably still there!) My conclusion: if you want Penstemons to live longer, just don’t water them so much!

And why can’t we extend this principle to most of our other dryland native plants as well? Let’s be sure to give plants a fair chance before we dismiss them. Once again, I don’t know how extensively some of the plants described by Kruckeberg were tried, so I acknowledge the possibility that I may be quite incorrect. Or maybe I’m just halfway incorrect: perhaps half of them will grow here under drier conditions, and half of them still won’t no matter what you try. (Like I said, I have a lot of work to do!) Maybe Kruckeberg’s perspective on dryland plants is reflective of a time when there were still a lot more undeveloped/wooded pockets in the greater Seattle area than there are today: perhaps the region in general felt a little more forested and less urban than it is today, when the book was first authored.

In what is probably my favorite native plant book right now, Wildflowers of the Pacific Northwest by Mark Turner and Phyllis Gustafson, the authors note that they “put particular emphasis on central and eastern Washington and Oregon and on the Klamath-Siskyou region in southern Oregon and northern California because most other field guides have glossed over these areas.” Wonderful, hooray for them, I say. Now if only gardening references would do the same! Even they, however, admit the shortcomings of their book. It is quite comprehensive, but not quite complete. Some plants are not pictured, only described briefly under the headings for related species; others are skipped over entirely. And of course, since it is not a gardening book, it only describes what the plants look like and where they can be found, not how to cultivate them. (Of course that’s perfectly appropriate for a field guide.) They also exclude any plants that don’t fall under the category of “Wildflowers,” such as our native trees and ferns. And finally, the photography is outstanding and more than worth the price of the book even if it lacked descriptions; but when you only see a close-up flower photo of Purshia tridentata or Luina hypoleuca, you are likely to think “what an ugly little flower” without knowing how cool the plant is when you see a whole one. So that’s not a complaint against the book itself, just an inherent shortcoming of a book of its nature and scope: you can’t get a feel for what many of these plants will look like in their entirety, or how they could potentially be used in the garden, from a book of this type. This book is excellent, and a valuable reference: get it anyways!

So, as far as I can tell, there is not really any one reference that brings it all together, communicating the exciting world of Northwest native plants in its entirety to a broad audience. While Kruckeberg’s book is excellent, I am daring to question whether some of the statements presented are not worthy of challenge. (Also, the book might have achieved broader appeal with more color pictures, especially of more obscure and interesting species. Having color pictures alongside the plants always helps make a book more accessible too, but I know that also makes it more expensive – oh well.) Wildflowers of the Pacific Northwest is superb, but it is a field guide, with its inherent limitations. Plants of Western Oregon, Washington and British Columbia by Eugene N. Kozloff contains an excellent collection of photos in the center section, but again most of these are close-up, and the text of the book is primarily botanical in nature with few tips for gardeners. (I won’t comment further on that one, because I haven’t looked at it very much, except for the photos.) And of course Hitchcock and Cronquist are great, but 98% of people, in other words most normal people, are not going to get excited about native plants from reading that!

Anyway, if you want to see more than eight species of garden-worthy native plants, you may need to get off the beaten path. Forget about looking in nurseries. Go explore for them in the wild. Go east! Go up! Follow the field guides and wildflower hike books, but don’t forget to look at everything – the ferns, trees, and plants that may have nondescript flowers but excellent foliage and form. And then recall that they’re perhaps not so difficult to grow as commonly believed. Maybe someday people will figure this out and we will see more of them in our nurseries and gardens.

Ceanothus integerrimus, a dryland naitve that is very showy and easy to grow.

Lomatium utriculatum, “Fine-leaf desert parsley” is a neat little dryland plant that even occurs west of the Cascades. I photographed it here in the Olympic Mountain foothills not far from our nursery.

Dryland Plant Management in the Nursery and Landscape

So, to follow up on a recent post, we hear that the proposed Seattle green code provisions have been shelved for now. Apparently they are going start over next year and consult various horticulture/landscaping industry representatives this time to draft a provision that makes sense. I have mixed feelings. Partly I almost think it would be (dare I say) funny to see the rule go forward more or less as originally proposed, just to see how nurseries and people would respond. Imagine Swanson’s selling 75% native plants… heh heh heh. Anyway, I read that there is going to be some big meeting about it on September 5th. I am really bummed that I did not get invitated, especially since all the ideas I sent them were so well-received by my readers (including many who didn’t comment on my blog). But I’m actually not that bummed, since we have a lot of things to do out here that are funner than sitting in meetings; and Seattle is far away, with lots of traffic, and politics, and people who sit in meetings. At least that is our perspective from the far away land of Sequim.

I wrote (more or less) against the rule, but (in part) not for the same reasons other people wrote against it. I really like this post about it by Mark Turner, a respected authority about native plants, who presents a very well-thought out and balanced view. On the other hand, I note that many of these letters make two major points which I believe are false: one, that native plants pose special problems when it comes to producing them in the nursery and/or growing them in your garden; two, that native plants offer such a limited selection as to be uninteresting or unexciting. I can see what people who make such comments are getting at, but ultimately I don’t buy either of these points as valuable refutations of the green code provisions as originally proposed. For me this whole issue really comes down to water use: that should be the central focus in crafting this provision. So in this post I shall attempt to demonstrate that nursery plants are not really that difficult to produce or cultivate. In a future post I may attempt to expand upon point number two.

In my letter to the Seattle City Council, I stated that “native and water-wise plants are, broadly speaking, not difficult to grow either in nurseries or gardens.” This is likely a somewhat controversial statement, since its runs contrary to what most other people writing letters to the Seattle City Council on this topic (at least, the ones I got to see) seem to think about growing our native plants. So while not everyone may agree with me, I still consider this to be a matter of education and adjusting to different practices from what nurseries and gardeners are usually accustomed to. For that reason I am happy to divulge some of our methods when it comes to successfully producing and maintaining these plants. Perhaps over the winter I will have time to revise and expand this into more of a formal article and put it on the Desert Northwest web site.

Dryland Plants in the Nursery

Some think that dryland and/or native plants are unamenable to nursery production and therefore will never become popular. Our starting assumption, then, is that there is nothing wrong with the plants, since they are obviously well adapted here, being native; so there must be something wrong with conventional nursery production. And, based on our experience, we find that the main thing that can go wrong with these plants is supplying too much water, especially in the summer. Most growers have their plants on a sprinkler system that is timed to water at regular intervals. Frequently the sprinklers are set to run for a couple hours every day (overnight, ideally) during the growing season. A few smaller growers hand-water everything and can use that method to regulate how much water plants get. It should come as no surprise that we do not believe one should indiscriminately water the crap out of everything in a climate that has a pronounced very dry season occurring reliably every summer.

So we don’t want to soak our plants to death with timed waterings, but we sure as heck don’t have time to hand-water it all either. So we have decided to say “no” to timers and “yes” to sprinklers. Using sprinklers, we water more or less often depending on what the plants need to maintain good growth, and on the weather. What this looks like is during a typical summer heat wave, the plants get water perhaps every 36 hours or so. During periods of cooler weather watering goes to a 60 – 72 hour schedule. We think it best to give the plants a very thorough soaking when watering, and then let the plants dry out somewhat between waterings. We just wait until they really need it before we turn the sprinkler on. (As an aside, some nursery people are afraid to thoroughly soak plants when watering, because they may get too wet and start to rot. We believe this is only a problem if your soil mix is too heavy, or if you are not letting the plants go dry enough between waterings.)

In conventional nursery production, the problem of keeping plants watered is frequently aggravated by over-fertilization. Potted nursery stock that is given the maximum amount of fertilizer it can handle without burning frequently develops an excess of top growth that is not able to be sustained by the amount of roots in the pot. Such plants also get very rootbound which is not ideal. Sometimes retail nurseries find themselves having to water such plants twice a day to keep them from drying, which is always a hassle. Additionally, once these plants are set in the ground it takes a couple years for them to develop a large enough root system to sustain the top growth. Although such plants will frequently come out just fine in the end with proper care, we don’t think this is the ideal way to grow plants.

Our method is to give plants basically as little fertilizer as we can get away with without compromising quality. Also, we use only organic fertilizers. Sometimes our plants may not look quite as full as conventionally grown stock (but then again, sometimes they do!) but we know that it is important to have a plant with a strong and healthy root system so the plant will experience little or no setback when transplanted to the ground. However – and here it might sound like I’m totally contradicting myself – “as little fertilizer as we can get away with” is often more than might be expected for certain plants. For example, we find that Ceanothus and Arctostaphylos are pretty heavy feeders in general, and sometimes surprisingly so, despite their preference for harsh sites in the wild. Really clever soils people could probably explain this, but all I can say is “go figure.” (Well, now that I think about it, there might be some connection with their adaptability to fire ecology.)

Some people – and we went through this phase for a while there – think dryland plants need extra gritty soil for the super good drainage they need to survive in containers. This, we think, is sometimes a little bit true, but mostly not really. As long as you are not watering too frequently – and that’s the important part – most dryland plants will grow just fine in an ordinary, reasonably well-drained commercial potting mix. This is even true of seriously deserty plants like sagebrush. A bark-based mix with some pumice is ideal, and a little compost won’t hurt anything either. It’s true that certain plants require extra grit, but these tend to be in the minority (unless you are specializing in alpines, in which case you probably already know what you are doing and don’t need to read this). Beyond “alpine” it is difficult to generalize about which plants these are: usually just a few species per large genus. Cacti and succulents are a mixed bag; many of these do require gritty soil, but a surprising number of hardier types really don’t care what you put them in and may even respond to a richer mix by putting on vigorous growth; bearing in mind the aforementioned caveats about watering.

Finally, since we have dry summers, a lot of our native plants are adapted to stop growing in the summer. We find that they are better not messed with in summer. Potting up, planting out, anything that involves messing with roots should be done in spring if possible; the second choice would be fall. Of course they’re not doing much in winter either, and wet/rot can be an issue when transplanting at that time, though many species don’t mind.

Dryland Plants in the Garden/Landscape

Water-wise plants, including our dryland natives, may fail in the landscape for numerous reasons, but I think the most frequent are too much water, not enough water, and inadequate soil preparation. There are definitely some misconceptions that need to be addressed in this area. For one thing, dryland plants are (for the most part… most succulents excepted) not so tough that you can just plunk them out in a harsh, awful site with terrible soil and not water them at all. Why not, you ask? They’re native. Well, when something seeds itself in the wild, the first thing it does is send a taproot straight down into the subsoil as fast as possible so it won’t dry up in its first summer. The same species planted out of a container doesn’t have this advantage (especially if the soil has been compacted or scraped off), so it will need a little help to get established.

Time sequence of container-grown plant vs. self-seeded plant.

In actuality, native plants, generally, will appreciate much of the same treatment that is usually provided for “normal”/”conventional” (whatever) plants: they respond as well as any plant to soil amendment and mulch. The main thing one must do differently is watering.

But let’s back up for just a moment and address soil amendment. This does not have to be complicated. Some swear by double digging, but we are of the opinion that this is generally unnecessary. Usually a healthy top-dressing of compost, left on the surface to decompose over time, does the trick. If you want to use less compost, even a little circle of it around each plant, several inches deep, goes a long way towards successful plant establishment. The only time we might not think soil amendment so important for dryland plants is if you actually have existing native topsoil at your planting site. Unless your house is really old, this is probably not you. Usually the native topsoil is scraped off and/or compacted beyond usefulness during new construction.

So, having amended the soil and mulched – and mulch an be a lot of things, including wood chips and rock; but not beauty bark, which is evil because it does not promote healthy soil – the big question is how to water. It probably goes without saying that dryland plants will not grow in a swamp, so we will assume average to well-drained soil here, though a surprising number of these plants will be fine on heavy clay as long as it dries out for a couple months in summer. The best way to water is with the watering basin method. You want to finish your planting hole with a nice, big, deep watering basin so that when you go to water you can fill the hole up all the way, and the water will work its way straight down into the soil. This will encourage deep rooting, as opposed to the shallow rooting that often takes place under conventional irrigation that only sprinkles the soil surface. How often you will want to do this depends on your soil, and how established your plants are; but generally you will want to do this as infrequently as you can get away with before your plants start to wilt, which may be anywhere from about once per week to once per month during the dry season. So we see it is not really a major time-consumer, because you are not out there all the time watering things by hand daily: you just have to pay attention. You’d better believe those new little plants are sending roots straight down as quickly as they can during this process.

Plant root development under various watering techniques, redrawn from The Dry Gardening Handbook by Olivier Filippi.

Conventional methods, by contrast, suppose that once you have installed your irrigation system and set the timer, you can pretty much forget about things. This mentality leads to the failure of native plantings that end up getting too wet. It is motivated by the short-term convenience of not having to pay attention to the planting and hand-water until the plants become established. If we consider how much it costs to install and maintain an irrigation system (they always break, of course), and the cost of all the water that is used, perhaps we can say it is time to re-educate people about more practical ways to create sustainable plantings and gardens. A little more care in the first year or two after planting goes a long way towards sustainability of a water-wise landscape.

And that is where I shall leave it for now. I hope that has been helpful, or at least interesting.

On a completely different note: you still have one more day to come and visit us at our September Open House! Don’t worry, we haven’t sold out of awesome plants yet. Come and see us if you can!

Seattle Green Code Provisions: Over the Top?

This may be difficult to believe, but it appears the City of Seattle is in the process of drafting some provisions that may be controversial. This time since it relates to horticulture, and particularly, to my area of emphasis (water-wise plants) I have decided to get involved. Unfortunately I don’t have time to write a really detailed post on this, and anyway, it all happened pretty suddenly. So I will totally flake out here and refer you to for the full story in their words. Actually, they sum it up better than I probably could anyway.

I have decided to write a letter in response to this provision. You may wish to do so as well if you read this on time and don’t mind staying up late: the deadline is tomorrow! (If enough people ask for an extension, though, who knows? Perhaps they’ll offer another comment period.) So here is a copy of the letter I am sending for all to see. It would have been nice to have a few days to leave this posted here and bounce ideas off my readers, before officially submitting it. In any case I would welcome your comments.

Before getting on to the letter I guess I should say one more thing. All this talk of rules and regulations is rather obnoxious. Some might ask, why do we really need anyone telling us what we can or can’t plant? Isn’t this just another government infringement on individual property rights? (The examples of cities prohibiting front yard vegetable gardens come to mind.) Actually (trying not to get too political, heh) I usually tend to be rather sympathetic to such sentiments; as long as people are being fair about the distribution of finite resources and not infringing on the rights of others. In writing this letter I am assuming, based on my reading of historical trends, that the implementation of this provision in some form or other is pretty much unstoppable sooner or later, so we might as well make the best of it. Put another way, if we’re going to be stuck with more rules, let’s at least have rules that make sense. This is how I justify the inclusion in my letter of ideas for how to draft this rule.

All right, so here it is:

August 26, 2012

Attn: Kathleen Petrie, Green Code Provision Taskforce & Seattle City Council
700 5th Ave, Suite 2000
Seattle, WA 98124

To whom it may concern:

I am writing to provide my professional opinions regarding Section 4. Invasive species and native vegetation portion of the Green Code Provisions for Healthy Landscapes under proposal.

I am the owner of a nursery that specializes in water-wise plants including many native species. Since I agree that gardens use far too much water, and are often planted using plant choices inappropriate to our summer-dry climate, I applaud the spirit of the rule. However, I would like to address some problems that would arise if the rule were drafted exactly as proposed, and suggest a number of changes. Because I like to be helpful rather than merely criticizing things I don’t happen to like, this letter will be heavy on ideas, of which I hope that some may be found useful in crafting the final draft of this provision.

As a basis for my suggestions, I must begin with a brief assessment of the adaptability of native plants to urban environments. Many people assume that because a plant is native it can automatically tolerate difficult or harsh conditions without special care. In actuality a large proportion of our native plants are best adapted to grow in the forest’s shade or riparian or wetland environments, and thus make poor choices for urban gardens where sun and reflected heat are common, especially in new plantings. Even those that are adapted to grow in the sun cannot always be considered sufficiently tough, since they will take several years to establish, and may languish if planted without proper soil amendments and irrigation for the few years it takes to get established. For these reasons, despite the benefits of native plants, I do not believe using native plants in the large numbers suggested by “75% of all new plantings” in the proposal is a very practical approach to the objective of water conservation. Furthermore, it may result in significant outcry from a gardening public who feels their planting options are suddenly far too restricted, as well as from the nursery industry which depends on the sales of a wide variety of garden plants to thrive.

Therefore, I would like to propose some possible alternatives to be considered for modifying the provision, which are as follows:

1. The definition of “native plants” is expanded to include plants from the dryland regions east of the Cascades, and Oregon and California.
2. The term “native plants” is replaced with “plants native to summer-dry climates” (from a list of world regions with such a climate).
3. Restrictions could be placed on what can be irrigated, and for how long after planting, regardless of plant origin. This would be my professional recommendation as the most sensible approach in drafting the provision.

I spell out these options in greater detail below.

In option #1, the definition of “native” plants is broadened somewhat beyond western Washington. Inclusion of plants from the dryland regions east of the Cascades, as well as plants from Oregon and California, would give gardeners far more planting choices for their landscapes than those only “native to western Washington.” A large proportion of plants native to the aforementioned regions are very much appropriate for urban settings, perhaps more so than many of our own native plants in many instances.

In option #2, the provision would be changed from reading “native” plants to read “plants native to to summer-dry climates”, which would include the entire western region of the United States, the Mediterranean, central Chile, and a few other parts of the world. This gives gardeners yet more options while maintaining the objective of reducing water consumption.

Before getting on to option #3, here I must include my thoughts regarding native vs. invasive plants, emphasizing that a very great majority of introduced plants are not invasive. Given that the plant species and cultivars that have been grown in the Northwest throughout history range in the tens or perhaps hundreds of thousands, yet only a handful of these have posed a serious invasive threat (I base this on the list provided on the website of the Washington State Noxious Weed Control Board); I conclude that a very small percentage, such as perhaps 0.1% or less, of all cultivated plants possess the potential to be invasive in the Pacific Northwest. While I can see supporting the removal of existing populations of invasive plants in some way or other, I do not consider “invasive potential” as a sensible restriction on plant choices, or support for the exclusion of non-native plants generally.

Of course, no matter what kind of plants one chooses to plant, it is still possible to use water irresponsibly. Under guidelines requiring a certain quota of native or water-wise plants, it is easy to foresee a frequent scenario play out in which all the right water-wise plants are installed, then irrigated excessively for the indefinite future under oversight that does not know any better how to maintain such a planting. For this reason I present option #3, a water-use based rule; based on the principle that a truly effective provision focuses not on the selection of plants themselves, but on the purposes for which plants are irrigated, and for which irrigation systems may be installed. By extension, I would put forth that watering native or water-wise plants for the first two years to get them established, then withholding water thereafter; is an idea worthy of support: watering any planting indefinitely, whether the plants be native, drought tolerant, or not; is not beneficial to the end goal of creating landscapes and gardens that reduce water use.

Here I would like to note an important exemption: Plants that produce food or meet some other significant utilitarian goal (bamboo for poles, for example) should be exempted from any rule regarding both plant selection and water use. The reasons for this should be obvious, but homeowners need to have the right to produce their own food without undue restraint. Let’s go after big water users like unused expanses of lawn and large-scale ornamental landscapes full of water-loving plants, not homeowners striving towards independence from big ag and reducing their carbon footprint.

Therefore (clarifying, I hope, my option #3 here), a sensible provision is one establishing that all new plantings (excepting food crops, as noted above) may be irrigated only for the first two years (perhaps three), and allowed no irrigation beyond natural rainfall thereafter. It doesn’t so much matter what plants are used: after two (three) years, they have to be tough enough to survive on their own, or not. This permits the broadest possible range of water-wise plants for use in gardens and conserves water by pulling for landscapes and gardens that can sustain themselves (as far as water is concerned, at least) in the long-term; and protects the rights of homeowners to grow food. It also leaves room for people to grow certain slightly thirstier plants they may feel they can’t live without, by means that have no impact on municipal water consumption, such as the incorporation of rainwater catchment systems and rain-gardens into the landscape.

Now for some further thoughts about how this provision may relate to the nursery industry. I strongly believe that native and water-wise plants are, broadly speaking, not difficult to grow either in nurseries or gardens. I feel qualified in saying this since, at our nursery, we propagate and produce all of our own stock. It’s true that certain species pose challenges, but perhaps not disproportionately so when compared with conventional or water-loving plants: in many cases, growers and gardeners simply need to be re-educated away from conventional higher-water-use practices to succeed.

I have independent data demonstrating that at least three quarters of plants offered by Northwest nurseries are native to parts of the world having climates where reliable, significant summer rains occur. An astounding number of these (48% of all nursery plants in my study) are native to eastern Asia, including our beloved Rhododendron hybrids, Japanese maples, flowering cherries, and a huge range of other ornamental shrubs, trees and perennials.

I believe the scarcity of water-wise and native plants in nurseries is based partially on supply and demand, yet also (much more so than people usually think) on what growers choose to produce and market. I therefore think it would be helpful to add an incentive for nurseries, landscape contractors, and related businesses to market/sell/use water-wise plants (meaning, those native to summer-dry regions of the world, or whatever criteria from the options above are chosen). For example, if Bob’s Nursery in Montlake can be determined to sell water-wise plants as 75% or more (or whatever number is chosen: this is admittedly arbitrary) of their total stock, they would be eligible for some kind of bonus or tax exemption, or a greatly reduced municipal water rate, or some such incentive. This would both raise awareness of the issue in general throughout the nursery industry, hopefully providing growers to move more towards the production of water-wise plants; and push the nursery business to diversify their range of water-wise and native plant offerings at the expense of thirstier choices; which, I believe, may be a tall order but certainly not an impossible goal to achieve.

I predict that there will be major obstacles to the success of this provision without the support of the nursery industry, since they are the ones who supply our landscape plants through a variety of channels. This ties in with another good reason to change the criteria for plant choices to something beyond just natives: if gardeners are given a wider range of drought tolerant options, there may be fewer objections among the general public at not being able to get their favorite Rhododendron or Japanese maple at a local nursery whose selection of such plants is vastly reduced from what it was. I believe it is important that this provision be crafted in such a way as to deliberately compel nurseries to provide more options for water-wise plantings, rather than just drafting it with only the landscape/garden in mind leaving the business end of this to fate.

One more idea that may be useful would be for the city to initiate and maintain a “trial garden” to determine which plants meet our region’s criteria for true drought tolerance. This, I think, would have to be quite extensive to be worthwhile; but the educational value of such a garden could be very much worth the trouble and expense. The OSU trial gardens at the North Willamette Experiment Station might serve as a model for such a trial garden, though their plant selection has been more limited and focused on specific plant groups than what is needed here.

Finally, on the subject of preserving existing native plants, I would prefer to include for protection only certain vulnerable or particularly enigmatic species (for example, garry oak). There seems little sensible purpose in preserving something like the ubiquitous Douglas-fir or a field of horsetail.

While I could ask the expected questions about how the terms of the provision will be defined and who will enforce them, I will leave such questions for others to ask as I am not a Seattle resident.

Lastly I would like to request that the comment period be extended. There are far more people who need to know about this provision and have the opportunity to comment.

Thank you for your consideration of this letter. It is my hope that some of the ideas I have presented may be helpful. As described, I believe some significant changes need to be made for this provision to be sensible, realistically enforceable, and able to achieve its desired ends. Please feel free to contact me if you have an interest in discussing this further or any other questions.

Ian Barclay
The Desert Northwest
PO Box 3475
Sequim, WA 98382

How to prune your Leyland Cypress

This episode of “What Were They Thinking?” is brought to you by Independent Bible Church of Port Angeles, Washington.

On the east side of the facility is a row of formerly healthy Leyland cypresses (Cupressus x leylandii), which have now been handily butchered by, I suppose, a tree service.

Now this doesn’t bother me a whole lot, as far as feeling sorry for the trees. Leyland cypress is probably the most over-planted conifer in the Pacific Northwest. They are way too darn many of them and they are usually planted in spaces that are far too small.

The problem is that somewhere along the way, someone—actually, a lot of people, apparently—started recommending it as a “hedge plant.” But the thing they forget to tell you is that it grows 90′ tall, so to use it as a hedge, you have to prune the whole thing annually – which is a whole lot of work and cannot easily be done for most people without special equipment, once the plants pass 12 – 15′ tall or so. Hey, coast redwood (Sequoia sempervirens) makes a great hedge, too, if you prune it often enough! This is the same sort of tree, folks.

The other reason I am not really bothered is that I don’t consider Leyland Cypress to be that attractive in the first place. Now actually, I admit, it does not look half bad if one compares it to a lot of other conifers. But to me it is ornamentally inferior to both of its parents, Cupressus nootkatensis (Alaska Cedar) and C. macrocarpa (Monterey Cypress). (C. nootkatensis has also been called Chamaecyparis nootkatensis and a couple other things – Xanthocyparis nootkatensis may be the best choice for those wanting to really stay current – but anyway. . .) Now I know that Leylands have been promoted as more widely adapted than both parents. This may be true, but as all these trees are perfectly happy in Port Angeles, that is not a consideration in this instance. There are some fabulous examples of the at once strikingly rugged and beautiful Monterey Cypress around town. I’m not sure why anyone who could grow it would rather have a Leyland!

Mostly, though, I think that this pruning just simply does not make sense. Some of the trees have had 90% of their foliage removed and will not recover. My opinion is that for what they did to these trees, they might as well have just cut them all down, and saved themselves some money on all that fancy pruning. I guess it would not be the first time in the history of the universe that an uninformed decision was made regarding tree pruning.

If Leyland cypress grows too large for this spot (as someone apparently felt), this is simply a case of the wrong plant being chosen for the site. Perhaps something like Portugese laurel (Prunus lusitanica) would have worked out better. It would only grow to 40′ in the time it takes Leyland Cypress to grow 90′, and if it gets too broad (as would be likely, if it is not pruned regularly) it could be cut back hard and still regrow.

Finally, this gives me the opportunity to say something that has bothered me for a long time about church landscaping. As far as I have ever seen, it is always really old-school, and really boring. Lots of beauty bark, or shall we call it ugly-bark. Lots of Rhododendrons, Pieris, and yawner plants that look like nondescript green blobs 11 months out of the year and require tons of summer water. Lots of green grass and little blob-shaped purple-leaf trees. Irrigation is a must: I don’t think I’ve ever seen a dry garden at a church. One gets the impression that whoever is in charge is severely lacking in imagination, and if the appropriate talent and creativity is available, it is not being tapped into. If churches are so keen on appealing to people maybe they should step outside of their little prefabricated suburbanite bubble and do something interesting. As far as I have seen, even urban churches that think they are hip are guilty of this lack of creativity and have the most boring plants/landscaping on the block. And don’t tell me it’s a money issue – they seem to have a lot to spend on irrigating and maintaining grass, and (dare I say) pruning trees. If anyone knows of a church that actually has interesting plants or landscaping, I’d love to hear about it.

Oh, and if you have planted a leyland cypress hedge, you’d better start pruning it now, or else save yourself the hours of agony and cut it down. You have been warned!

Has the word “nursery” lost its meaning?

It’s time once again for more of a rant-style post. And this is going to be a long one, as in loooooong with lots of extra o’s. But it’s more than just a rant: it’s also a splendid collection of astute observations, ending with a challenge. And I had better mention that I’m not doing this just because I think it’s fun or like to be negative. It’s more that I think I am asking some very important questions that people ought to stop and think about.

A few posts back, concerning trends in nursery business models and marketing, I posed the question, “is the past the key to the future?” I noted very briefly a number of subjects surrounding this question where the game has changed considerably in the past 50 years; and, not surprisingly, there is much more to be said about how nurseries have responded to these changes, or in some cases failed to respond to them. Most importantly, as we look to the future, one has to assess “what we should do” as a business to succeed and remain relevant and competitive into the future. So having said that, I had better preface this post with an important point. I recognize that everyone has to find their own path to success (or at least try!). So it sounds like I’m trying to tell everyone how to do things, but I realize it would be pretentious of me to assume such a position; especially with my business only in its very early stages, with little going for it that may appear decisively “successful” from the outside. The disclaimer, then, is that these ideas are just that, ideas; and they are my ideas, which means I allow plenty of room for disagreement. Fire away! So, here we go.

Back in high school, when I first began taking an interest in plants, one of my favorite nurseries was a place called Olympia Greenhouses. (I would be thrilled, by the way, to hear that any of my readers remembers this place in its original form!) Olympia Greenhouses was among the last of a dying breed of nursery: the kind that propagated and produced plants on site, and sold them directly to the local community. When I walked into this place, it would be in varying degrees of disarray, with way too many of certain plants than could possibly sell, hundreds of giant houseplants, and a nursery yard going so far back you could get lost in it, with no possible hope of keeping it all tidy and under control. But that was all just part of the fun. You could go in there once a week and find something new—tucked away in a corner, or brought out of production—with each visit. And by something new, I really mean something old. Not the latest and greatest plants, but the one’s we’ve increasingly forgotten, in some cases for the better but often to our own loss.

In about 1996 (I think) this nursery was bought out by an owner (or group?) who was apparently totally incompetent and quickly ran the business into the ground. It soon closed, the greenhouses collapsed and became overgrown with blackberries and eventually alder trees, in which condition it has remained the last time I checked. Oh well.

Today I can count on one hand the number of these old-fashioned production retail nurseries in western Washington that have survived more or less in their original form (that I am aware of!). By far the best known is Flower World in Maltby. Another example (and I haven’t been there in years, so I hope they’re still around) is The Brothers Greenhouses, which is found along Highway 3 between Belfair and Gorst. I stepped in there and almost thought I was back in Olympia Greenhouses—although the selection wasn’t as interesting, the place had the same sort of feel. (They said they also did some wholesale, but it was really tough to tell who their market was—certainly not any of the local retail nurseries I have ever visited in the area.)

To be clear on what kind of nursery I’m not talking about: I can also think of a few nurseries who claim “we grow our own plants;” yet, while they may produce a proportion of their own stock, it’s obvious that they have also brought in plenty of plants from wholesalers such as Monrovia (as if they could hide those green pots!), and lots of bare-root trees and shrubs that they didn’t produce themselves. So they don’t count. Also, I’m excluding from this categorization nurseries that produce many of their own plants and offer some retail sales, yet have another major outlet (usually mail-order) for their plants. These are usually specialty nurseries and include Desert Northwest and a number of other nurseries that continue to do business this way (Raintree, Coenosium, Colvos Creek, Fancy Fronds, etc.)

The nursery industry has changed dramatically over the decades. It now appears that the majority of retail garden centers and nurseries now buy most or all of their stock from wholesale nurseries. For those that do continue producing some of their own stock, this seems to account for a continually decreasing proportion of their sales, with a trend towards producing only a limited variety of annuals with no other plant types represented. While the industry keeps trending in this direction, it’s rare that I see anyone stop to critically analyze the possible benefits and drawbacks that may result from these changes. (One could say that critical analysis in general tends to be severely lacking from the horticulture industry, and this is but one example – oops, did I just say that?)

In fact, I’m to the point of wondering why businesses that don’t produce plants should appropriately be called nurseries. My dictionary defines a nursery as “a place where plants are grown for sale, transplanting, or experimentation.” The use of the word “grown” in this context would appear to suggest that plants at a nursery are meant to increase in size while there. This idea stands in opposition to the usual intent of retailers, which is to buy retail-ready plants from vendors and liquidate them as quickly as possible, and in pretty much the same form. So I guess I have this novel idea that nurseries, to be worthy of the word, should not just sell plants, but they should grow plants. Businesses that have completely abandoned production might be more appropriately called “plant stores.” I realize that’s possibly a subjective point, depending on how much one wishes to stress dictionary definitions; but still, it bears contemplation.

When retail nurseries produced their own plants, that meant the people selling the plants actually had plenty of hands-on experience with the plants. They knew exactly what everything they sold needed to succeed in cultivation, because they had, in fact, grown it themselves. Now garden centers often pride themselves in having knowledgeable employees, yet it’s my observation that this knowledge is based more often on books, the internet, plant tags, and (everyone’s favorite) heresay than on personal experience. These sources of information are potentially less reliable, or sometimes inapplicable to our region, than good old personal observation of plants over time. Unfortunately, most people who work in retail nurseries don’t have sufficient funds or garden space to buy one of each plant offered and try it, nor do they have a chance to watch the plants over a period of time on the sales floor in the same way that they might at a production nursery. The result is that while the breadth of knowledge may be impressive, the quality of knowledge isn’t always adequate. Have you ever wondered why so much plant information circulating today is still just plain wrong, after we should have had decades to figure things out? Perhaps this is partly a result of this shift away from production by retail nurseries and corresponding tendency for many of their employees to lack the hands-on plant experience they need to discern such things. It’s something else to think about the next time you visit a nur – I mean, plant store.

Also contributing to the misinformation problem is the tendency of wholesalers releasing new plants to make definitive statements about their needs or features based on trials over an inadequately short time period or narrow range of climates. How can they really know how big something will get in 10 years? In 20? If it grows 10′ tall at the test garden in California, who’s to say how big it will get in Seattle in the same span of time? 3 feet? 15 feet? Or will it freeze dead the first winter? Now I know that sometimes growers and breeders do a better job than that testing new plants – but it’s still not always good enough to be sufficiently accurate. I have observed that, generally, retail nurseries accept whatever the wholesalers tell them and pass this information on to the customers without bothering about its accuracy. Is that really the best thing for the overall health of the retail business?

In fact, another more subtle phenomenon that has shadowed the shift of retail nurseries away from production is that, increasingly, plant breeders and wholesale nurseries are controlling the market. For a while I had doubts about whether this is true, since common theory dictates that the market is based on the demands of consumers. But if nothing else, I’m certainly convinced that the average nursery retailer has completely lost control, and this does not benefit the gardening public. The retailers should be the experts, and should be leading the way, and deciding what they sell based on what they actually want to sell. They should be able to discern that new plants promoted by plant breeders are not always superior to the old plants, and inform the customers. Instead, they (not without exception, but all too often) just play along with whatever the wholesale reps tell them, compromising their long term potential as a trusted source of garden expertise for their short term profit margin. Related to this, people are forgetting “old” plants that used to be more common and deserve much wider use. For example, Photinia serrulata is a useful, attractive, small evergreen tree that performs perfectly in Seattle, where it lingers in certain older gardens. But I can’t recall ever having seen one at a nursery. If the wholesalers don’t grow it, no one else does either, so people forget it exists. Or they’ll bring a piece of it into the garden center hoping to find someone who can tell them what it is, and none of the employees younger than 65 will be able to identify it, and if anyone wants to buy one, well they’re just plain out of luck because no one is growing it anymore.

SO… what’s the big deal? Maybe you’ve accepted all those trends as just the way things are. This is how it is in all the other nurseries, so why break the mold? But, all these other reasons (and nostalgia) aside, I can add a few very practical reasons why retail nurseries should seriously consider a deliberate return to production, and why I believe the future may, and should, see a reversal of the trend away from it.

Let’s consider for a moment what a retail nursery is paying for when it purchases a plant from a wholesale nursery. One must pay for the soil, fertilizer, and labor that went into its production, for facilities and maintenance, taxes, and (sometimes) for patent rights and water. One must also usually pay to heat greenhouses. You’re also paying for your friendly wholesale nursery representative. And I’m sure we could think of lots more expenses; that was just a quick list “off the top of my head.”

Then — the big one — one must pay for delivery. Even in those rare cases where there’s no visible “delivery fee,” we all know (unless we forget to stop and think about it – I hope not!) that you’re still paying for delivery, since the wholesaler has to absorb those costs somehow. I think we can safely predict that delivery of plants on trucks is not something that will get less expensive in the future. Obviously, producing plants on site eliminates these costs entirely—producing them off site a few miles away, under control of the retailer, reduces them substantially; and still has the side benefit of allowing for better control of one’s inventory vs. being at the mercy of wholesale suppliers.

And then – the even bigger one – wholesale nurseries have to absorb all those costs making only half as much money or less per plant as the retailer. Suppose a wholesaler puts $4.50 (all of the above costs together) into a 1 gallon plant and sells it for $5.00, keeping the remaining $0.50 as profit. In theory, the production retailer (assuming a professionally trained production staff and adequate facilities) should be able to put the same $4.50 into that plant and sell it for… $12? $15? I grant that keeping a sales staff and appealing customer experience adds a bit of additional overhead to the $4.50, but even so, it’s not unrealistic to possibly keep $5 – 6 or more as profit for the same plant!

(By the way – that math in the last paragraph is what we in the specialty nursery business call a trade secret. So, shhhh! Don’t tell anyone! Actually, anyone who has managed to read this far is welcome to it.)

And THENNN, we’re all observing a cultural trend whereby products shipped over long distances are increasingly less “cool” among those who decide what is hip and fashionable, than things produced locally. People want to “shop local” – why not be the first in town to offer locally produced plants?

ANNNND – yeah one more – as long as we’re taking about what people want (imagine that) – and tying into this problem of plant breeders and wholesalers controlling the industry – shouldn’t we be wondering how much longer customers are going to tolerate poorly adapted or just plain lousy patented plants that fail to perform as expected? I’m not saying all patented plants are necessarily lousy, but a surprising number of them are genetically weak or just aren’t bred for the Northwest’s climate. Meanwhile, wholesale nurseries push them into our marketplace at the expense of more appropriate selections. Will there be a backlash? Will gardeners someday start specifically avoiding the latest patented cultivars because they are skeptical of them in general? Who knows? – someday it could happen.

As far as I can tell, the main reason retail “nurseries” and garden centers are not interested in producing their own plants is they have established what they consider to be a successful model of business and would prefer not to change it much. But the time may come when this change may be necessary, and these businesses should be ready. We would all agree that there’s no point in sticking to your guns to the point where you start losing money and losing business to your competition. I’ve heard plenty of other reasons not to explore production, from the cost of heating greenhouses (which you essentially pay twice as much for when purchasing wholesale plants, as spelled out above), to the challenge of finding and training new staff. None of these excuses really holds water. To me, the best — perhaps the only — excuse for retail plant stores not to expand into production is the lack of available space. And even this may not be a workable reason forever, as many nurseries have found that substantially downsizing in coverage is what it has taken to get through our current difficult economy. Hmm, now what to do with all that “extra” space?

I’m not advocating a return to the past just because I happen to like it better. I think it’s partially true that what was unworkable about Olympia Greenhouses was partially its failure to adapt to a changing market at the time (although I also heard rumors of the new owner being a plain lousy and irresponsible boss making numerous missteps with management and staff). We can expect change to continue, and should always be ready to adapt to it.

But here’s one thing I think would actually be helpful to the nursery business: I would like to suggest a return to a gardening culture in which nursery people who sell garden plants are the same people actively involved in breeding, propagating, selecting and producing the best ones, rather than this ridiculous breeder to grower to broker to retailer chain we have now. I believe more than a few positive changes would result from this, all the way from quality of plant material and advice, to employee satisfaction; vastly benefiting horticulture and gardening culture at large. And that is just one reason why we at the Desert Northwest remain firmly committed to propagating and producing all of our own plants here on site. Anyway, this is getting so long, I’ll try to describe exactly what that would look like in greater detail in a future blog post.

In the meantime, just to be obnoxious (wasn’t that one of your New Year’s resolutions too?), I may as well go on labeling non-production “nurseries” as plant stores. If we don’t draw the line somewhere, the word nursery as it pertains to horticulture loses its meaning.

Peninsula Gardens, Gig Harbor, Washington in 2007. A classic example of the “plant store” business model (in their later years at least), they are now out of business.

Derby Canyon Natives, Peshastin, Washington. Although many of their plants go towards restoration projects, and the like; at least they are a grower that sells directly to the public. (I had such a hard time finding a photo of just the sort of nursery I am talking about that this was the closest thing I could think of!)

Garden Show Dreaming

So, the 2012 Northwest Flower and Garden Show came and went last weekend. At first I was going to pass on commenting, since there are plenty of other voices out there chattering away about this year’s show, mostly expressing disappointment: some nicely, and some less so! And we would all agree it gets a bit obnoxious to read criticism after criticism all the time. Another thing I’m noticing is that many other people (my “plant friends”) have the ability to make scathing criticisms sound nice and diplomatic, much more so than do I; reducing the chance that anything I present as criticism could be seen as anything other than obnoxious, even if meant to be constructive. So that would be one reason to stick by the idea of “if you can’t say anything nice, don’t say anything at all!”

Then I had the idea that I might write something nice about what I liked about the show, giving criticism a pass; since there were, in fact, a few things that I liked and even found inspiring. A lot of people didn’t think the gardens were much to look at this year (if they could see them – a frequent comment was that lighting was inadequate), but I noted some very interesting water features that were pretty cool. The childrens play area continued to be good; at least my kid liked it. The section reserved for various plant societies, gardens and arboreta was good, even if a couple societies I would have liked to see represented were missing – the Cascade Cactus and Succulent Society, for one. And that is not necessarily the fault of anyone running the show, I suppose.

I also liked (conceptually, at least) the little cards that were distributed at the ticket booth to incentivize showgoers to participate in a survey to provide feedback about the show. While one could be a bit annoyed by the tactic of baiting people with offers for coupons from various booths (which were so scattered that it would take considerable effort to visit each one deliberately) to get them to participate in the survey, at least they deserve credit for doing something to try to feel out what people want out of the show to guide its future. But, to make it sound like the whole show was just fabulous in every respect would be kind of phony – and I think few readers who attended the show would find my commentary to be believable.

So here’s my idea to try to remain focused on being constructive and providing solutions. I’m going to spend just a little time fantasizing, shall we say, about what I would like the show to be. I’ll present my thoughts in the form of advice or suggestions for improvement that might be implemented by show operators, while acknowledging at certain points how I compare these ideas with the current situation (in which case, sounding critical cannot be avoided). Hopefully I’ll avoid the usual “The ____ was too ____. Wah wah wah.” style of complaining. However, I should emphasize from the outset that this is not necessarily intended to represent what everyone wants: it is just what I would like to see. I don’t pretend everyone else gets the same things out of the show that I do – nor should they, as we all appreciate different aspects of gardening, and for different reasons. So this is an entirely fantastical post, in which I invite the reader to share in all, some, or none of my sentiments. But here are some ideas that, if put into action, would make the Garden Show really, really awesome according to the standards of Ian.

I’ll start with the plant market, since it has so much potential. The plant market should be much larger, and should be the place in the Northwest – heck, this side of the Mississippi – to find the rarest and most exciting plants in the trade. Gardeners should be looking forward to their one chance every year to get hold of all the coolest, newest, and most obscure goodies for their gardens. (Heck, this idea by itself might even sell more tickets, if successful!) To that end, the show administrators should actively pursue the best, most prestigious, and most unique nurseries for the plant market. The nurseries should be tempted with an offer they can’t refuse! As it is, they seem to be leaving things largely to fate; and, between the economic downturn and society’s changing interests, fate has not treated the nursery business well the last few years. The plant market used to be pretty good; but still, I think, short of its potential 10 to 15 years ago. Every year a couple more nurseries drop out; and now, well, I’m sorry to say the plant market is a shadow of its former self both in terms of size and diversity of offerings. I appreciate, though, that the plant market is still in a prominent location in the show, rather than tucked away in a corner.

Next, I would be excited to see the show to do more to distinguish itself from “home shows.” This is actually related to the previous idea, since much of the space that ought to/used to be the plant market is now occupied by vendors of replacement windows and gutter systems. Dear show owners: people can find this stuff anywhere. There are home improvement shows all the time. The Northwest Flower and Garden Show is the second biggest in the country: how about differentiating to demonstrate that it is also the best? I would propose as a solution some sort of sliding scale where the most desirable nursery vendors pay less for a booth space and home improvement type vendors pay more and get last priority. Also related to this, artist and all other product vendors should be directly related to gardening. Vendors of scarves and jewelery, again, can be found at a variety of shows; and represent an opportunity for the show to differentiate by pursuing vendors with more clearly garden-related products to replace them.

Now, to the gardens. I feel that half the problem with the gardens are the themes chosen each year that the designers have to work with. This year’s theme was “A Floral Symphony.” Last year’s theme had something to do with stories or books, I can’t rightly remember. So here’s my idea. It’s true that most anything in life – music, books, attire, what-have-you – can be related to gardening. I would like to propose that these pre-selected themes be based on topics that are inseparable from gardening. I think this requirement would keep things a little more down to earth and less fantastical. Because what I’m seeing is that the gardens don’t always look realistic to people; and it is not always simply because of practical concerns (expense, maintenance): I think sometimes a “weird factor,” if you will, appears when a theme is chosen that results in certain elements being included in the gardens that overshadow the strong points. Gardens need to look like something someone would actually do. And in many places, they do: the question is, how to make it better? Hence my suggestion that gardens ought to reflect a garden-based theme. I don’t really have any specific examples in mind. It’s just a starting point to help the gardens hopefully inspire a broader range of showgoers.

Here’s another idea. I would like to suggest the addition of a large area where specimens of individual plants can be showcased and judged: sort of like they do at the county fair, only with much higher standards for coolness and acclaim. (Perhaps a few more of those gutter system vendors could be eliminated to make space for this – ha ha.) We have a place for showcasing container displays; which is great. We have a place for showcasing artwork. Why not a place for showcasing plants? These plants could be judged and the best given awards just as the other categories present at the show. This could also be a way to generate interest in particular new or rare items of great horticultural merit that deserve broader attention. I think a display of, say, 100 – 150 individually presented cool plants, that were truly unique and interesting; would be a lot of fun to look at, even if not all of them happened to pique my interest personally. Hopefully most of these plants would be produced by smaller and edgier growers and not just the big guys, so some method of regulating that to make it fair for everyone would have to be developed.

Finally, I would like to say that I have no serious complaints about the speakers line-up. I would just like to offer one minor suggestion, which would be that at least one seminar per day should be about exploring for plants in the wild. This is because I think people benefit from seeing the connection between gardening and nature in a way that goes beyond “landscaping for wildlife” and such: gardeners can never have too much awareness of the wild origins and habitat preferences of their garden plants, or the story behind their introduction and cultivated history. These talks usually draw pretty good crowds anyhow, at least the few that I have attended.

So, you folks organizing the show do all that, and then I’ll be really excited to come every year! I’ll even be a vendor with my own booth! Really! And I’ll talk it up to everyone. So, really now, what’s not to like about my ideas? Does anyone have more inspiring ideas to offer? What would get you excited to see the Northwest Flower and Garden Show? Not that anyone important is actually going to read this, but hey, let’s put it out there just for fun.

Once nice water feature.

Another nice water feature. The funny thing is I didn’t really notice that bird until I went back and looked at my pictures. What does that say about me, I’m not sure?

This cool rotating metal thingammy (not sure what to call it really) was probably the most oohed and aahed at thing in the gardens. I liked it too. The water feature behind it was also pretty cool. On the other hand, I’m not exactly inspired to go out and buy a rusty guitar sculpture for my garden.

The WSNLA Treasure Island booth looked good once again although we did not participate in it this year.

They did offer a few of our plants though, which appear to have mostly sold, so that was nice.

This Hardy Plant Society of Washington display of purple and black leaved plants was way cool. Just one problem, almost nothing in the display is hardy. As much as I loved this display I thought that fact was a bit ironic.

The North American Rock Garden Society display looked great and I enjoyed chatting with the fellow who staffed the booth. I will probably join this society soon; it’s very reasonably priced.

I leave you with this lovely poster from the Plant Amnesty booth: proof that not everything has to be inspiring to be worth seeing!

Reactions to Newly Unveiled USDA Zone Map

The buzz of the horticultural world lately has been the release of the new USDA Plant-Hardiness Zone Map. So, since I am an avid amateur dabbler in all things weather and climate, I thought I might as well chime in. This actually happened a few weeks ago so I am a little late getting into the game, but hey, better late than never!

The USDA zone map was first developed a long, long time ago when dinosaurs roamed the earth. Based on a long-term average of the coldest temperature to occur each winter at a given location, it was intended to serve as a general guide to discern in which parts of the country certain plants could succeed based on their cold-hardiness. It has since taken on many different forms and grown into an industry-dominating monster with its own will far beyond that of its creators. Think I’m exaggerating? Read on.

Now the new map, it must be said, is far more accurate than any of the preceding maps (which include a couple of “botched” versions I will not discuss, to keep this from getting any longer). A major complaint about the 1990 map (the previous major USDA map produced) (warning: really big download) was that it was based on an anomalously cold period in history; thus, it made everyone look colder than they really are. It was also based on a very short time span of just 13 years. Why? Well, that’s the big question, isn’t it? No serious, professional climatologist or meteorologist uses a period that short to determine averages or “normals” for any meteorological purpose. When you look at the “average” high or low for a given date on the TV newscast or online, it is based on a much longer period: 30 years is the standard for the National Weather Service. It’s hard to dispute that this use of a 13 year sample was a deliberate and foolish decision, although I’m not quite sure whose or why. In any case, once people realized winters weren’t going to continue to be as cold as they were from 1974 – 1986 (the period used), the need for a new map was urgent. So, faster than the speed of government, we have our new 2011 map, which happens to be based on data from 1975 – 2005 since we have to allow them a few years to figure out what to do with all those data (for more specific details on the history of the maps, see “Further Reading” below).

But – lest I sound too cynical here – the new map is accurate. How do I know? Well, it’s because I’m one of those nerdy people who has independently researched the matter in great detail over the years. When the new map came out, I was impressed: it broadly agrees with my calculations for USDA zones at dozens of locations in the Pacific Northwest. Many of these I provide for you below. I should mention that I am not the only one who thinks it is quite accurate: many established industry professionals and avid hobbyists alike – at least, those who are closely tracking the weather – would agree with me. While new map is generally accurate, it is not perfect. But it is as good as it’s going to get considering the amount of data that are available.

What do I mean by “accurate” but “not perfect?” Here’s one example of why not having enough data compromises accuracy. In the Puget Sound area of western Washington, nearly all of the weather stations with decent periods of record are in average to cold microclimates and mostly not that close to the moderating influence of salt water, despite that the majority of people with gardens tend to live in relatively close proximity to the water. Anecdotal evidence clearly tells us that a lot of sheltered microclimates close to the water are well within zone 9, which on the map just barely shows in just a couple tiny places (mostly over water). This assertion is also supported by a comparison of temperature data from personal weather stations, which have proliferated exponentially in just the last few years, with data from the official stations with longer periods of record. Rarely, we see this work the other way: in Port Townsend, the weather station is close to downtown and the water, and very mild; while Kelly and Sue at Far Reaches Farm, which is a couple miles inland, consider themselves to be about a full zone colder, supported (very importantly) with their observational data from the last few winters. With the weather station being in the mild spot, the colder microclimates just outside of Port Townsend don’t show up so well.

But all this is small beans: the map is still pretty darn accurate, and as accurate as we can ever expect it to get. Enough said, right? Oh, just wait…

Now I’m seeing a variety of responses to the new map, but I will just offer my thoughts on a couple of the most common ones I see. Some, upon seeing the new map, put it forth as evidence that our climate is getting warmer, since many of us have moved up a half zone or so from the 1990 map. Frequently, these people are not aware that the 1990 map was based on an anomalously cold period in history, as I have described above. In fact if you go back even farther and look at the really old 1960 zone map, it’s pretty darn close overall to the 2011 map (except for being colder in parts of the Intermountain West):

(Incidentally, I know that out there somewhere is a detailed, colored, 1960 zone map; with a and b zones. There used to be a poster of it on the wall in the WSU halls of the horticulture department. I wish I had taken a photo of it because I have never found it online. Has anyone seen this? Let me know!)

Now I’m not a “global warming denier,” but I get a little irritated when the people with the most passion about this subject tend to lack the science to back it up. Sure, our climate’s getting warmer, but it has little to do with this map. I also find the number of news releases citing the new map as direct evidence of global warming to be pretty ridiculous.

Then – and I’ll spend much more time on this one – we have people who are convinced beyond any doubt that the map is not accurate, as if this were some kind of vast conspiracy. I have carefully avoided getting into big arguments about this on several occasions since I think these sorts of debates are not usually helpful without the chance to present my case in its entirety (and hear theirs out in detail if they have one). For example, one of these was (or, should I say, might have been) with a lady from Boise – a very experienced gardener and plantsperson – who seemed to be not taking the map seriously when it put Boise in zone 7a. The thing is, statistics don’t lie: if you take the average of every winter’s coldest temperature, and it comes out between 0 – 5°F, you’re in zone 7a and that’s that. Did I go wrong somewhere?

Well then once that point has been made, the response tends to be (and here I’m speaking generally, not of the aforementioned person – which I’d better say just in case she reads this!), “Then the USDA zones need to be adjusted/are not really that useful/whatever.” OK, so why not just say that in the first place? Don’t go saying “There’s no way we’re in such and such zone” without statistics to back it up – pretty please. It’s not like we can deny how the weather is. When was the last time you heard someone say “It’s 45 degrees out! It has to be!” when the thermometer shows it’s 55 degrees? With USDA zones, the only difference is it’s not happening in the here and now, so you have to actually go back and look at the historical data.

I can only conclude that the reason a lot of people don’t trust the map is that it does not fit their perception of reality, or of some notion (of vague origins, but very strong nonetheless) of “What My Zone Should Be” (and sometimes other people’s zones too!). Now I know that much of this discrepancy is based on actual plant performance, which is important to discuss since, supposedly, the main function of the map is as some sort of predictor of plant performance. So how did this discrepancy arise? Let’s consider an example: Some (not me!) might suggest that, say, Arbutus unedo will grow in Boise because it’s rated hardy to USDA zone 7. What I want to know is, why, when a discrepancy arises, do so many gardeners immediately distrust the map? Could it be that perhaps Arbutus unedo should not be rated to zone 7?

And I actually think this is the major problem with our understanding of USDA zones: PLANTS ARE NOT ACCURATELY RATED FOR THE RIGHT USDA ZONE. And now that we have a good, trustworthy map, it is the only problem (considering the limitations of the system in general, as I will discuss below). Prior to the 1990 map, it seemed that plants were often rated a bit too optimistically, but things still jived well enough that no one made a big deal over it. Now that we have the new map, the discrepancy is even greater!

So who’s behind all this? Gardeners get plant-hardiness ratings from many sources: books, plant and seed catalogs, growers’ tags, and the internet, to name a few. Ultimately the problem is that, somewhere in the pipeline, someone draws assumptions about plants and climate zones without sensible supporting data. Based on my observations, I would say growers’ tags are especially problematic: many companies/tags/etc. will rate a plant’s hardiness according to its ability to tolerate an average winter in the zone number it is assigned, seeming to forget that weather deviates significantly from average from one year to the next. For example, I often see Cordyline australis rated as “zone 8.” What is up with that? It is certainly no hardier than 15°F. Even at the top end of zone 8, you’re likely to drop below 15°F at least once or twice in 10 years – enough to freeze your plant to the ground — and at the bottom end, forget about it; you’ll be lucky if you ever get it through two winters in a row.

And this isn’t just a problem with a few certain plants. If you start looking carefully at books, and plant tags, and comparing these ratings with actual results with the plants (in their respective zones as they truly are); you will notice that most of the time plants are rated with the same degree (pun intended!) of inaccuracy; and, I think it’s fair to say, based on the same faulty assumptions.

Now we begin to understand the “problem” with Boise. (And anywhere else, too, but I’m using Boise, not because I like to pick on them, but because it is a nice extreme example of how deviation from average messes with zone ratings and the assumptions surrounding them.) So it’s zone 7a: but during the time period used in the data sample, the coldest temperature recorded was -25°F! Now how many plants rated to zone 7a can live through that? A couple other winters were close to that as well: the climate of Boise exhibits extreme deviation from their average coldest temperature every winter. Boise has also had a lot of mild winters (especially recently) with no temperatures anywhere near 0°F; and — wouldn’t you know it — these have to be averaged in as well to compute their USDA zone!

So it’s easy to see what motivates a perception that the map must be lying to us – or even a desire to “keep” Boise in zone 6 (or even 5?) if such a thing were possible. Nurseries want gardeners to succeed with their plants. When customers ask nursery staff in Boise why they can’t recommend plants that are rated to zone 7, they need to have a succinct answer that doesn’t call their grower’s tags (and hence, the integrity of their product) and reference books (potentially associated with the integrity of their expertise) into question. Maybe it’s just me but I would call this a mighty big problem.

And if we look just a little further at “who’s behind all this,” one more interesting factoid comes to light. When the USDA published the 1990 zone map, they also published statements about each zone with a list of plants that can be “expected” to be found within that zone. For example, within zone 9, one usually “expects” to find Phoenix canariensis and Grevillea robusta, among others.

I believe this to have been huge tactical error: not that it’s terribly wrong in general, but because it sets forth a backwards way of thinking about zones. Many gardeners, including the very experienced and professional, have become so firmly convinced that certain plants are “zone X plants” that they think (usually subconsciously, and without admitting it) that plants can tell us better than historical weather data what zone we are in. Sure, plants can tell us a lot: it’s where I get some of my anecdotal evidence for zones locally in a region I am very familiar with. But to draw conclusions about zones based on plant performance observations always requires support from hard weather data first and foremost. Frequently, our firmly entrenched “zone X plant” categories often tend to be based on incorrect information, as described above. What we need is for zone ratings for plants to be based on actual evidence based upon the zones, not the plants. For anyone to draw conclusions about their zone based on whether a “zone X plant” will thrive in their area, is to look at this all backwards.

What we also need is to get back to the original intent of the map, which is as a general guide. I hear a lot of gardeners who claim this mentality, yet still look with extreme suspicion upon that Grevillea which is in fact hardy to zone 8b, when considering it for use in zone 8b; or who refuse to let go of their “zone identity” because of their plant-zone-based perceptions, regardless of what maps and statistics tell them. In both cases we see how firmly conclusions about the USDA zones in which we garden are rooted in the assumed accuracy of zone ratings assigned to plants, which are assigned by people who usually remain (for most purposes) completely anonymous to the end user, and are called into question all too infrequently.

So, what to do? I almost think a rigorous national campaign to re-assign zone ratings to garden plants is in order, but if the USDA takes charge of this, our climate may have completely changed again in the time it takes them to produce any results. But in any case, the line of thinking would go like this: Will Arbutus unedo grow in Boise? No. Therefore, it’s not a zone 7 plant. Will Cordyline australis grow in zone 8 in western Washington? No – therefore, it’s not a zone 8 plant. Will Grevillea robusta grow in zone 9 in downtown Port Townsend? No, so it’s not a zone 9 plant. It’s just a plant. It’s not a set of historical climate data used to determine a USDA zone. Now (perhaps slightly tangentially) this way of looking at plants will also result in some additional discrepancies highlighting the need to think of the map as no more than a general guide. For example, Carpobrotus edulis grows happily in zone 8a in New Mexico, but can’t handle zone 8b in Washington. This is because of other climate factors such as summer heat, and light and precipitation patterns throughout the year. Climate is ultimately regional, and plant performance is ultimately based on empirical evidence: hence the limitations of the USDA map are significant. To their credit, the USDA is pretty clear about this stuff on their new web site.

And in case reading this hasn’t made you completely confused yet, I’ll just add this: In my conversations with customers, I notice that gardeners in western Washington often experience hardiness let-downs based on cultural conditions. For example, if you plant that Grevillea in rich, heavily amended soil and water it all the time, so that it keeps growing into the fall and fails to harden off; it should hardly be surprising that it takes a hit when that “Arctic blast” comes along. When we pamper our plants more than they get pampered in nature, hardiness often suffers. Of course there is a time and a place for soil amendment and watering – for example, I would pretty much always recommend amending severely degraded or compacted soils – but balance is needed. Back to the point, though; this is just one more factor among many that often skews our perceptions of plant hardiness.

So where does all this leave us at the Desert Northwest? Well, I haven’t been rating hardiness for the plants we sell according to the USDA zone system – not yet anyway. Basically it’s because I don’t want to mislead anyone, since it’s hard to predict how readers of our plant descriptions will understand a zone rating. I prefer to assign actual temperatures at which a certain plant will be damaged, killed, etc. with some wiggle room for other factors as described above (duration of the freeze, etc.). These are generally based on actual experience growing them here in western Washington, or our best educated guess. Also, not infrequently, we make the comment in our plant descriptions that such-and-such is likely to be hardier in a climate with hot summers. We figure a lot of plants (though not all) that just make it in the Pacific Northwest can probably handle temperatures a full zone colder in the Southeast, or nearly; and we make note of it. Finally, we wish to emphasize that plants don’t look at maps or weather data, and sometimes the only way to determine whether something is hardy enough for your garden is to try it and find out, and sometimes more than once. We do plenty of that around here!

Do I sound mad? I’m not really. At least, not in a bad way. But I’m definitely crazy. And to prove it, just for fun, here are some USDA zones for a number of randomly selected Northwest locations, which I calculated based on official historical climate data. The middle column is the average of the coldest temperature every winter between 1969 – 99. The source for nearly all this data was accessed via this page on the ESRL web site. Through this page you can do your own independent research if you like, and I think you will be surprised with the accuracy of the map! (Note: for the most part, my results agree with the map pretty well, or are a little lower than what the map suggests. This discrepancy is because the data below are based on 1969 – 99, not 1975 – 2005 as in the map. The period of 2000 – 2005 had mostly very mild winters in the Pacific Northwest. Thus, Boise, for example, shows as 6b here rather than 7a, since the milder winters in the early 2000’s are excluded.)

Aberdeen | 19.97 | zone 8b
Anacortes | 17.3 | zone 8b
Battle Ground | 12.93 | zone 8a
Blaine 1NNE | 11.37 | zone 8a
Buckley 1NE | 13.8 | zone 8a
Centralia | 13.03 | zone 8a
Chelan | 4.47 | zone 7a
Clearwater | 16.2 | zone 8b
Coupeville 1S | 15.2 | zone 8b
Dallesport Airport | 7.93 | zone 7b
Darrington | 7.53 | zone 7b
Ellensburg | -6.83 | zone 6a
Elma | 13.6 | zone 8a
Elwha Ranger Stn | 17.3 | zone 8b
Everett | 15.37 | zone 8a
Forks 1E | 17.03 | zone 8b
Goldendale | 1.23 | zone 7a
Kennewick | 3.97 | zone 7a
Longview | 16.33 | zone 8b
Olympia Airport | 8.57 | zone 7b
Omak 4N | -6.2 | zone 6a
Othello | -2.23 | zone 6b
Port Angeles | 18.97 | zone 8b
Port Townsend | 20.9 | zone 9a
Pullman 2NW | -5.6 | zone 6a
Quincy 3S | -5.17 | zone 6a
Richland | 4.03 | zone 7a
Sea-Tac Airport | 18.57 | zone 8b
Spokane Airport | -7 | zone 6a
Stampede Pass | 1.53 | zone 7a
Stehekin 4NW | 3.9 | zone 7a
Wenatchee | 4.37 | zone 7a
Yakima Airport | -3.27 | zone 6b

Ashland 1NW | 14.0 | zone 8a
Bandon 2NNE | 22.7 | zone 9a
Bonneville Dam | 17.17 | zone 8b
Brookings 2SE | 29.4 | zone 9b
Elkton 3SW | 19.3 | zone 8b
Eugene | 15.33 | zone 8b
Gold Beach | 27.3 | zone 9b
Grants Pass | 16.2 | zone 8b
Hood River Exp Stn | 6.43 | zone 7b
Klamath Falls 2SSW | 0.23 | zone 7a
McMinnville | 15.63 | zone 8b
Medford Airport | 14.8 | zone 8a
Newport | 21.2 | zone 9a
North Bend | 24.87 | zone 9a
Oakridge | 14.77 | zone 8a
Ontario | -4.93 | zone 6b
Portland Airport | 17.93 | zone 8b
Salem Airport | 13.43 | zone 8a
The Dalles | 9.73 | zone 7b
Tillamook | 17.37 | zone 8b

Boise | -2.7 | zone 6b
Lewiston Airport | 3.07 | zone 7a
Moscow | -8.13 | zone 6a
Riggins | 6.6 | zone 7b

Further reading about USDA Plant Hardiness Zones and the Map:
Plant Hardiness Zone Maps: The Rest of the Story by Tony Avent
Plant Delights’ January Newsletter, discussing the new map and what went into it by Tony Avent
Climate Zones Gone Wild! A basic introduction, by me, 2008.

A Window to the Past

So, I hope we all survived the holidays with class – I know I did. Yesterday was my 33rd birthday. Though I may now congratulate myself for having exceeded the average male lifespan in 9th century England, I’m not really old enough to call myself old, nor do I especially want to. Some of you reading this are probably like “oh, he’s still a young’un.”

So, being relatively less old than many people, I don’t exactly have a great feel for what horticulture and gardening used to be like, say, 50, or 100 years ago. And many from among the earlier generations, from whom much could potentially be learned, don’t tell me about this subject; because as the nursery business has morphed over the years many of them have inadvertently abandoned the specialty nursery market to get sucked into the boring world of conventional horticulture, and/or been deluded into buying all their plants at box stores, so our paths never cross. But whenever I manage to learn something about this topic, it’s usually interesting.

So recently I happened across a book at Goodwill, called Rhododendrons of the World, written by David Leach in 1961. At 50 years old the book is pretty much an antique, yet it was in perfect condition. With 550 thick, letter-size pages I had thought it may be worth a fair sum of money (for example, in Powells’ vintage book section, or whatever it is) though it is listed online mostly in the $30-60 range. But at Goodwill it was $4, which, I thought, was good enough for me. $4 isn’t much to part with even if I’m not really that into Rhododendrons.

Anyway, it’s a spectacular book. Every aspect of Rhododendron history, culture, and descriptions of species are spelled out in meticulous detail. Then there is an appendix at the end listing several thousand (!!) Rhododendron hybrids and their ratings and features. Intended to be comprehensive, it shows that even 50 years ago the number of Rhododendron hybrids already in existence was truly immense.

Here are some thoughts I had after spending some time with this book. It is apparent that people were really into plants and gardening then, leaving one to wonder what happened later that things seem to be so different now.

First of all, the internet and all that comes with it is definitely making people stupider. Oh, wait, did I really say that? I mean, attention spans continue to be on the wane – mine too. I can’t think of many serious horticulturists today who could read a book this long and comprehensive, let alone write one!

This book is some incredibly deep plant-geekism coming from a horticulturist. The only work that compares in scope and detail (that I can think of) that I have in my possession from the modern era would be The Grevillea Book, by Olde and Marriott. I suspect this book did not sell as well as the Rhododendron book because Grevilleas are still not widely grown outside of Australia. But more importantly, these two are trained botanists first and foremost (though I think Marriott has, or had, a nursery). I find it curious that great monographs seem to be always written nowadays by botanists, not horticulturists. Could one consider this an area of deficiency in the horticultural realm?

But you don’t just get the feeling that the author was the only one who was into Rhododendrons. Hundreds of other people are cited and many of their actions involving Rhododendrons are described. An extensive list of Rhododendron breeders and their work is provided. There is also the definite sense that this book is written to an established readership of avid horticultural fanatics. From his writing style, one gathers that he’s not trying to win anyone over to Rhododendrons: everyone just loves Rhododendrons. Nowadays you can start reading a gardening book and feel midway through that the book is still trying to sell itself. This tells me that people just aren’t that into plants or gardening anymore, in general. I sort of knew that already, but it is interesting how that fact comes through by comparing garden books now with 50 years ago.

And (did people ever stop to think? Do they now?) why Rhododendrons? That’s really a great question, considering there are so many other kinds of plants in the world. There’s no denying that the decades-long obsession with Rhododendrons has permanently influenced the gardening culture of places where they can be grown, including the Pacific Northwest. Just look around; now we have a million Rhododendrons everywhere. They’re a part of our culture we can’t shake off. You could say their popularity still hasn’t ended. Any retail nursery in the Northwest is pretty much expected to have a Rhododendron section, and usually an extensive one with an excellent variety from which to choose. You could say the “fad” continues to this day, though the excitement has diminished somewhat along with gardening in general. We are left with the remnants of a passion that we forgot we had, or why we had it. But, looking to the future, as I tend to do; I like to think that the genus Arctostaphylos, our western-native “Rhododendrons,” (think about it – they’re in the same family!) has the potential to be just as exciting.

In the back of the book were numerous appendices, including one providing a list of nurseries where you could buy Rhododendrons, including quite a few of them in the Pacific Northwest. I only recognized a couple of their names. Now you have to wonder: what happened to all those other nurseries? What did they look like in 1961? What kinds of plants did they sell? I would be intrigued to learn more about that. Sometimes the past is the key to the future. Sometimes old geezers who think young people don’t care anything about what they have to say and therefore don’t make the effort should speak up and share some of the horticultural history they keep within their memory.

Meanwhile (because it wouldn’t be a blog post from me without one really cynical paragraph) everyone in my demographic has finally abandoned World of Warcraft to try to figure out how to get into the housing market which usually involves cutting all costs not deemed as absolutely necessary. This cost-cutting means there’s no point in shopping at your independent retail nursery (let alone a mail-order or specialty nursery!) when “we all know” that the cheapest source for landscape plants is the big box.

So before it starts to sound like I’m completely rambling, I’d better attempt to tie things together. The changes I note in the last fifty years of Northwest gardening, are but a few small pieces of a much larger and complex puzzle; which involve societal change and fragmentation, globalism, changing trends, a growing discontent among younger people, a shrinking middle class, and a challenging job market and housing market.

So what does it all mean? Is the past the key to the future? I have also been at times politely critical of nurseries that seem to go on as they always have, pretending nothing has changed. What is the appropriate balance when assessing the past vs. the future of Northwest gardening and nursery culture? Now I must admit, I have no shortage of ideas and views about this (what a surprise, right?), but they’re complex enough to be worth several blog posts; so, more to come! For the present, I leave this post open-ended: I am sincerely interested to hear your thoughts.

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