Checking on cheatgrass
When you work with invasive plants on a regular basis as I do, there is a fairly high expectation that your own property will be devoid of unwanted invaders. I happen to love weeding, and for the most part things are looking pretty good in my backyard. The small amount of diffuse knapweed and Dalmatian toadflax are under control with biagents (natural insect enemies), and several years of hand-pulling hoary alyssum has proven effective. But then there’s the cheatgrass. Oh my!
Cheatgrass, also known as downy brome or what many locals simply call “speargrass,” is unquestionably loving the weather this spring. I cannot remember wading through thickets of it before and it’s going to be a literal pain to deal with in a few weeks.
For humans, the seeds can be mildly annoying and somewhat painful when they penetrate socks and laces. But for our beloved dogs, it’s far worse. The seeds can lodge themselves in their paws, ears and can burrow through their skin resulting in both internal and surface abscesses. Seeds can even be inhaled when stuck on a favourite tennis ball.
Few places in the Okanagan are immune from this invader. While cheatgrass thrives on open dry sites where soils have been disturbed, it can also invade shady, moist sites. This extremely aggressive and ubiquitous grass has invaded most of the grasslands and low elevation forests in the Okanagan and Similkameen valleys. It is particularly prevalent along trails, roadsides, abandoned fields, burned areas and sites heavily grazed by livestock or wildlife.
This annual weed was one of our earliest Eurasian invaders, arriving to the Columbia Basin in contaminated seed in the 1890s then spreading via the railways across the west. It grows on all exposures and all types of topography from desert valley bottoms to local mountain peaks. Mature cheatgrass can be as short as one inch and normally does not exceed two feet, however this year is clearly an exception.
In the coming weeks, cheatgrass will change colour from green to purplish-red to brown as the plant matures and eventually dries. Branches are slender, drooping and hairy, hence the alternate name downy brome.
Because cheatgrass grows throughout fall and winter, by the time the rain stops in spring, cheatgrass seeds are already maturing. Unlike native bunchgrasses, cheatgrass then dies by the end of July, avoiding the hottest and driest part of summer. This gives it an advantage over native grasses. When dry, cheatgrass is extremely combustible and can represent a major fire hazard.
So, how to deal with this invader? Minimizing soil disturbance and maintaining vigorous perennial plant communities can prevent new infestations. If you have cheatgrass on your property, hand pulling can be effective for small infestations, especially before the plants set seed.
On larger infestations, mowing or weed whacking plants will be the better option. Control will be required for several years due to seeds in the soil continuing to germinate. Regardless of the option you choose, the area should be seeded to perennial grasses to help out-compete the cheatgrass and lessen your work in future years.
To help your canine companion, make sure to give him a good brushing when you come back from your walk, visit to the dog park or camping trip. Pay particular attention to paws, checking the webbed areas between the pads and removing all seeds. If your dog is shaking his head a lot or scratching his ears, there could be a seed in there which requires veterinary attention. Your dog will thank you for the extra attention! For information on invasive species go to our website: www.oasiss.ca or contact the Program Coordinator for the Okanagan-Similkameen, Lisa Scott, at 250-404-0115.