Knapweed picking at Battle Bluff trail

Story courtesy of Philip Lawson

Our group of six volunteers gathered at Lac du Bois Grasslands Protected Area near Kamloops to pull invasive knapweed from the Battle Bluff trail. We started at 9:45am and were out by 11:30am, it was quite an enjoyable morning!

In total, three bags full were collected, primarily around the abandoned station-wagon on the south face and also on and beside the trail leading in to it. The ‘rosettes’ of the plants, the small new plants that will grow into flowering plants next year, are almost impossible to pull out effectively by hand without a trowel. If left until next year, they will develop into full plants and pull out quite nicely by hand, just like the ones we got this time.

We have interrupted the seed distribution cycle by removing the flowering plants before they go to seed, for this year. When we pull the mature plants next year, we will have dramatically reduced the plants ability to spread and invade the adjacent grasslands. In subsequent years, the new plants will number less and less and can be pulled when we encounter them during group outings around the end of June, catching the plant at its most developed stage but before the seed heads form and open. Knapweed seeds remain viable in the ground for up to eight years!

Knapweed hasn’t been completely eradicated from the area but there is a chance to prevent it from taking over these grasslands, like it has in other areas. It is a beautiful trail to travel – and if you had to ‘work’ anywhere, you couldn’t find a nicer place!