Why aspens aren’t the best white wood tree
If you’ve ever seen my crew and I out working, you’d know we both could easily be singled out for public humiliation on the fashion show “What Not to Wear.” I’m sure Phipps and I have committed many fashion faux pas on a day-to-day basis as we dress to work in the gardens of Douglas County – I’m shamed to admit we are both over 50 and resolutely will not give up our jeans and work boots.
The fashion mavins would have us attempting to bring some femininity to our work style. We both do try to have our socks at least match our shirts. Plus we never, ever wear white after Labor Day. Does that count?
Speaking of fashion . . . one can’t help but notice definite signs of landscape fashions (to me, landscape fads) infilling the empty spaces of people’s gardens.
So, in the context of raising the public’s aesthetic conscience, I bring you “What Not to Plant.”
And before the landscapers jump into the fray, just let me say I feel it is the responsibility of the landscape industry to lead the way to healthy, happy, vibrant landscapes. Clients, customers and newcomers are not as savvy about the area as we are, hence, it is our responsibility to educate and inform through example, through our work, and by what we ourselves use and install. Right now the tail wags the dog, so to speak.
Topping the list of landscape errors and aberrations is the abundance of aspens being used in the Valley.
I know, I know, we all love our native aspens. But, really! They are so fraught with problems–disease, insects, poor rooting habits, an unequivocal thirst for water, suckering habits that drive a gardener mad, etc., etc. With a life expectancy of 10 to 12 years before running out of vigor, aspens should be one of the trees we go to the mountains to admire. We shouldn’t subject them to abject misery in our lower elevation gardens.
In native habitat, they grow in moist soils, in shaded groves on north mountain slopes, thriving in large stands that include the mother tree, diminished by age, yet surrounded by saplings representing the growth potential of her root suckering. Even in native stands of aspen, you’ll find damaged and diseased trees. But when looking at a grove that represents one genetically non-diverse being, you tend to overlook the runts.
It may be windy in the natural aspen settings, too. But, our lower elevation winds literally can suck the moisture (what little there is) from the air, the leaves, the soil, our skin … you get the picture. The wind and lack of humidity are far more severe in the lower valleys then the high elevations.
For aspens, if conditions aren’t to their liking, they’ll respond by quickly catching one of several diseases, from bacterial gumosis to cystopera canker, compounded by aphids, black spot, lack of vigor, and overall ill health.
Plus they hate alkaline soils (higher pH) and/or salty water which occurs naturally in some of our low and high elevations of the Valley.
They simply aren’t meant to grow, thrive, and endure in our Valley. As you drive up Highway 88 and climb in elevation, you’ve reached aspen Shangrila. Here in their native woods the trees are in the proper environment for continued good growth.
It’s aspen nirvana.
Nothing can compare to aspens, but there are other trees better adapted to our climate. Any reputable nurseryman will be glad to show you some beautiful alternatives.
Nothing can completely replace an aspen. Now our birches are fighting the bronze birch borer (a topic for my next article), so we’ve lost another white-barked alternative to aspen.
Still there are two good alternatives. Both develop whiter bark as they age. For right now you should avoid the white barked birch like Jacquemontii, as they are very susceptible to borer damage.
The following are the two best birch to shop for: the best cultivar is heritage birch, betula nigra ‘heritage’. Another birch almost resistant to bronze birch borer is monarch birch, betula maximowicziana.
For a narrow, columnar form in the landscape try columnar Euorpean hornbeam.
There are also columnar red oak that will have fiery red color in the fall as a bonus.
These are all more adapted to our climate and have the added bonus of long life.
They’ll be viable in the home landscape for years to come.
n Tina Fixman is a horticulturist who lives in Minden. She’s been self-employed in the landscape business since 1992 having previously worked as an extension agent, nurserywoman, and landscape foreman. She now proudly calls herself a “girl gardener.”