Weeds…..Unwanted Guests
When I closed my eyes, I could still see them.
In 1990, my wife, Peg, and I became new stewards of a 55-acre farm/timber parcel of land near Deary, Idaho. Until we purchased it, about half of the land had been planted to grain crops; the remaining land was forest and wetlands. We had enthusiastic plans of restoring the farmland to a more natural condition in order to improve its value as wildlife habitat. Ponds were dug, trees were planted and native grasses were seeded. As with any restoration project, disturbance brings not only desired plant species but also some undesirable ones – weeds. Initially, the weed we squared off against was Canada thistle (Cirsium arvense (L.) Scop.). For hours at a time, we’d haul backpack sprayers around the property and dose every thistle we came across with Curtail R, the herbicide of choice at the time.
Which is why I could see the plants even when I closed my eyes at the end of the day.
Little did we realize that dealing with Canada thistle would be remembered as the good old days. Since those early years, we’ve seen the encroachment of several more aggressive and invasive weeds on our property. These include: cheatgrass (Bromus tectorum L.), an introduced winter annual grass that is widely distributed throughout the western US; oxeye daisy (Chrysanthemum leucanthemum L.), an escaped ornamental that is now widespread in the Northwest; orange and yellow hawkweed (Hieracium auraniacum L. and H. pretense Tausch.), introduced herbs found in many areas in the Northwest; spotted knapweed (Centaurea maculosa Lam.), an introduced biennial or short-lived herb ; sulfur cinquefoil (Potentilla recta L.), a long-lived introduced perennial herb; and most recently ventenata grass (Ventenata dubia [Leers] Gross. & Dur.), a very fine-leaved annual grass introduced from Eurasia.
Of these unwanted guests we have been able to control the oxeye daisy, the two hawkweeds and the Canadian thistle with herbicides. We have been able to control the spotted knapweed by hand-pulling individual plants because we observed it early. Because sulfur cinquefoil looks very similar to native cinquefoil (Potentilla gracilis Doug. ex Hook.) it didn’t catch our attention until it was quite widespread over a 17-acre area on the farm that we had never mowed or fertilized. Last summer we pastured 16 rams in this area, in the hopes that they would help us stop the spread. Their grazing gave us the desired clipping effect and an abundant amount of natural fertilizer. While it is a bit early to tell what affect this treatment has had on the cinquefoil, it appears to have benefited the desired perennial plants, especially the grasses.
Peg and I have learned some valuable lessons concerning weed management. The most important is to be familiar with the vegetation. When you see a new plant, determine what it is and whether it’s beneficial to your land. If it’s not, it’s much easier to control or eliminate before it has a chance to spread.
Now when I close my eyes, I drift off in a peaceful sleep, knowing our land is providing healthy forage and cover for our wanted “guests”, the wildlife.
Jim Kingery is Professor Emeritus in the Rangeland and Ecology Management Department at the University of Idaho. Jim’s research interests include restoration of disturbed lands.