The Gardeners Downfall- Trees


I was inspired today because this is not only my favorite time of the year, and favorite time of the year to plant but my most favorite time of the year for trees. Somewhere, someone wrote that trees are the most satisfying thing you will ever plant. They are a gift to to the next generation.  September and October are fine months to plant trees- provided you follow a few basic rules. But trees are also addictive and as any gardener knows they are the source of everlasting lust. The problem with trees is that most gardens just don’t even have close to enough space to deal with the lust. A deep, primal, arboreal lust.

Damn, that grew fast.

In case you haven’t noticed this climate is ideal for growing trees. We grow the hell out of trees and export them and their fine wood all over the world. In fact, our state tree Pseudotsuga menziesii (Douglas Fir) probably once had specimens that soared to over 400′ tall before greedy loggers, drunk with the lust of fortune whacked them down. Mind you that is taller than the current world champion Redwood which I think is 379′ if current information is to be believed. We can grow trees and well. The problem of course is that most gardens are sectioned off into lots 50′ x 100′ on average. If you have more than that, MUCH more than than that then curse you but I am trying to appeal to the average gardener. The choices of course are endless. And if you know Sean Hogan, the choices are mind boggling and  dangerous. At Xera we challenge ourself to limit the amount of trees that we grow. And it is FAR FROM EASY. If Greg and I had our way we would be a freaking arboretum. But I digress and instead we try to choose trees for smaller gardens- a bit off the ordinary and within the scope of our enterprise.

Yep, I did that.

One of the first gardens I really had free reign was located on a lot 30′ wide and 50′ deep. Did you think that stopped me from jamming as many trees as possible into that garden? Nope. My delusion was real and I squeezed trees into every conceivable nook and cranny. I know visitors were just being polite but they had to see my delusion even though I was blind. So, damn blind. 6 Eucalyptus? Sure! Evergreen Magnoliaceae- of course, Eucryphias- how about every freakin’ species?   Quercus- holy hell did i go through a lustful period for evergreen oaks. The thing is that when a tree is small and when you have lost your mind in lust it is an illusion that it will ever grow. And of course they do- its Oregon. We grow god damned trees here. So- Do as I say and not as i did. Think oh, so carefully before you go down the forest path.


Really big. And this of course depends on how long you intend to be in a prospective garden, but remember that trees get big. And they can be sneaky and deceptive. One moment you are cradling a sapling in your hands, then next year- damn…that grew fast. Often they will go through a slow youthful period and then before you can say “compost” they hit their stride and growth is exponential. If you haven’t done your research, measured your choices and pulled yourself back from the brink there can be disaster.  What you require is a good dose of reality. And I suggest that before you plant a tree- any tree that you make sure to visit a mature specimen in the flesh. Nurseries, with display gardens, parks, what little and pathetic arboretums we have here, private gardens. All are valuable visits to give you perspective. Even if the tree you lust for does not yet have a 50 year old specimen or more- look at others in the genus that are closely related. For instance years ago, I lusted for Quercus hypoleucoides Silver Evergreen Oak from SE Arizona. I could not find a specimen more than 10 years old at the time- and to be realistic even then they were mighty and beyond the scope of my garden. Instead I visited several evergreen oaks that I knew were more than 50 years old on the University of Oregon Campus. And that, as they say set me on the course of reality.

What the Hell have I done?

First and foremost selection should fit into several attainable criteria. And lets be realistic, none of us lives forever and we probably won’t be staying in the same garden for the rest of our lives. We are a transient lot gardeners- ever happy to pull up roots and start anew. But trees are big- permanent things and once they are up and going its more than a financial commitment it comes close to civic. Lets begin with the climate zone. Trees don’t fall under the same rules as say a Gardenia or a Pelargonium. Instead of pushing the zone you really have to think long term. I like to follow the rule not of the average USDA zone per year but rather over a 10 to 20 year regime. For your information the coldest temperature recorded at PDX in the last 30 years was 9ºF (December 22, 1990).  So to begin that means a tree whose life span will most likely be decades should at least be cold hardy to the worst we can expect. Follow this rule carefully- a tree should be hardy to at most zone 7b (5º to 10ºF). You do not want a 30′ tall tree to freeze to death. This is real money and risk. If you live in Hillsboro- that temperature is 3ºF Zone 7a (0º to 5ºF)- and this isn’t a bad benchmark for the whole Willamette Valley.

Rot in hell

Trees cause shade. Well, most do, and this can be anathema to all kinds of garden plans. I have yet to see a successful vegetable garden in shade. If you want that then think carefully. One troubling trend is planting fruit trees all over the place. This is obviously done by gardeners that are hungry when they obtain and plant. Don’t do this. Unless, you have done serious research and have committed yourself to true dwarf rootstocks, this is a recipe (literally for disaster). Fruit trees are not dainty and space friendly. Those little gnarled trees you see in orchards in the Hood River Valley- those are CONSTANTLY attended to by professionals. Left unchecked a poorly thought out orchard in an an urban setting is basically a shade casting, fruit rot, yellow jacket attracting mess. And you better like apple crisp because there ain’t gonna be any tomatoes. Instead pick maybe just one fruit tree- your very favorite. Make sure that it does not require a pollinator, get disease, or grow into hogzilla the rotten fig maker. Do your research. Consider a dwarf or semi-dwarf variety. Take the time to learn how to prune it as well as water and maintain the tree. Fruit trees are not carefree.

Be realistic

You can’t have every tree. So make a list of criteria and follow it and do your research. If there is a large beautiful specimen several blocks away that you pass by daily- do you really need that tree? No. Enjoy it where you can see it. Instead, focus on what you really want, what you can attain, and then develop a list. Foliage? You like that? Check. Evergreen? Deciduous? Fall color? Check. Check, Check.  Bark. And since you will probably be staring the most at that make an extra check, check. For instance at Xera we grow Crape Myrtles for very specific reasons. They are within the size perimeters of urban gardens. They have ravishing bark, they bloom for one to two months and they get fall color. They also come in a wide array of sizes and flower color.  They are also disease resistant. Construct a similar list on your own and google the inter webs.  Japanese maples are perhaps the most planted smaller trees in our pervue. I have to say though that even if they come in a staggering array of shapes and colors and sizes they are afflicted by verticillium wilt. Thus rather than planting a whole collection of them, reduce your risk. Find the ONE that you cannot live without and plant that. Do you like flowers? There are any number of flowering trees- but they too are all over our city. A purple leafed plum may be at home in the parking lot at Walgreens- enjoy them there- because there you will never see, for instance, a Witch hazel- which demands to be observed up close and fits sweetly into smaller gardens.

Water, please water

Arboreal lust takes the garden to whole new level. Consider what you have, what you want, what you have space for and then make a smooth intelligent decision. Trees are about the future. Picture what you would like to see in not just 5 years but 10 and beyond. Consider the growth rate. You may not need to buy an enormous specimen- which i have found take just about as long to establish as smaller saplings. Look carefully at overhead power lines, distance from the house as well as checking underground lines- there is easy and enthusiastic help on these fronts. And then make sure that you follow a consistent regime of watering and mulch. This will allow the roots to dive down deep and attain even greater tolerance to dry conditions that our summers always bring- resign yourself to watering in summer for at least the first three years. A healthy tree is the most glorious thing you can grow.


The Gardeners Downfall- Trees