BC Range War: Gardens to Grasslands Alien Invasion

When it comes to range manage-ment in the beautiful Okanagan Valley of B.C.’s southern interior, ranchers have to manage not only for productive forage from the native bunchgrasses but also the complex challenges that come with being located in a valley that is growing in population and popularity.

Above the white sand beaches of Okanagan and Kalamalka Lakes are the ranges that provide grass for the herds of cattle that graze from valley grasslands to alpine meadows. With the growing population comes a growing number of alien species (in the form of plants) that are deleterious (harmful) to the precious plant communities. A listing of these would take volumes, however the top 10 of these species that impact the ranges is sufficient for any rancher, cowboy and otherwise beef enthusiast to rethink the notion it is easy to make a pound of beef in this mild clime.

All of these species come from across the waters from the lands of Europe and Asia. Having little or no natural predators or diseases in this new world, these species have thrived and are literally choking out the native plants that have survived for millennia. So here goes for a listing:

rangewar1306_011. Diffuse Knapweed Still King of the interior weeds but is succumbing to various biological control agents.






2. Spotted Knapweed Possibly Queen but also being slowed by bio-control.






3. Dalmatian Toadflax A lovely garden flower (if it would have stayed there) also being slowed by bio-control.






4. Hound’s Tongue A member of the borage family with a toxicity that can cause death if ingested by livestock.






5. Hoary Allysum Also called pepper weed, this weed can out-compete bunchgrasses.






6. Yellow Hawkweed Which one of the 21 species you have is anyone’s guess. This weed will completely occupy an area.






7. Orange Hawkweed Cousin to yellow hawkweed and equally competitive and aggressive, this weed loves wet areas.






8. Scotch Thistle Good name for a weed that will keep neighbours and livestock away. It stands up to six feet and has spines that will discourage most grazers.






9. Puncture Vine This weed will take out your bike tires and becomes problematic to feet of livestock. Loves the dry, sandy soils.






10. Rush Skeletonweed Perennial plant with roots that will out-compete most native plants.






11. Sulphur Cinquefoil I know this is number 11, however probably the worst rangeland weed there is. Will form a monoculture and out-compete all other plants.