If you garden or own a yard in Colorado, you can consider this summer your crash course in botanical diversity training. Or to use another metaphor, the lull before the big storm.
Why? Because not a lot is happening with emerald ash borer right now. State and city foresters and the state Department of Agriculture are working busily to watch for the ash-tree-killing insect’s spread. It has been confirmed in two additional square-mile sections of the City of Boulder — an expected expansion of the infestation there — for a total of 11. A new parasitic wasp is being released that preys on eggs. Cities and counties are inventorying trees and making plans. Will they treat with pesticides? Remove the ashes before the bugs get there? Or just take out the trees not doing so well in marginal places?
In this lull, the cities of Broomfield, Englewood, Erie, Lafayette, Lakewood, Longmont, Louisville and Westminster, plus Boulder County and the main University of Colorado campus wrapped more than 450 ash trees on public property in wide green ribbons. They did it to visually bring home how many there are and exactly what their loss will mean.
Also in the lull, an important word is circulating: Diversity. In that word lies hope.
The reason the Front Range has as many ashes in public forests as it does is that they’re easy to grow and inexpensive. Or rather, they were. And that’s why all over Colorado, you’re going to hear a lot in the next years about keeping the urban forest, and your own yard and garden, diverse.
In my yard, where the builders did nothing if they couldn’t do it cheaply, the tree list includes an ash, doing fine in a stupid place; a struggling locust and an aging crab apple. It’s too small a lot to have more than three shade trees. I’m lucky that at least one is beautiful.
In the rest of it, I’ve added: a Spartan juniper; three or four kinds of spirea; a barberry; eight different kinds of roses; two kinds of lavender, two of thyme, two of oregano, two of lavender, two of chive; three different currants, a black raspberry; bee balm, mint, tarragon, sage, tons of catmint; four kinds of penstemon; variegated and dwarf iris; two kinds of species tulips; two of daffodils; two kinds of dwarf mugo pines; Turkish veronica and a bully of a poppy mallow that spreads 8-foot tendrils and magenta blooms across the driveway, where I encourage visitors to park on it.
There’s also a gorgeous double lilac, planted by the previous owners. And chocolate flower and red birds in a tree and … still more.
I didn’t plan to embrace diversity. It just happened over years as I learned, bought and planted. The botanical universe is huge, and I love so much of it that hewing to a landscape plan’s logically designed visual “beats” feels restrictive (and … expensive). I also possess a constitutional inability to resist a plant sale. The result is anything but disciplined and anything but finished (two of those penstemons are still in their pots).
So while it wasn’t deliberate, I can certainly claim diversity as a mission I’ve achieved.
And when I do have that ash removed, I’ll look around for a replacement tree species that isn’t already in everybody else’s yard.
Susan Clotfelter: 303-954-1078, sclotfelter@denverpost.com or
