The Weed Warrior: Knapweed and blueweed don’t need no herbicide

The Weed Warrior: Knapweed and blueweed don’t need no herbicide

Weed Warrior Frank

For effective knapweed or Blueweed control, from spring to fall, if you do not want to use herbicide, you can employ the millennia-old hand-pull method. Then garbage bag your weeds for the dump. But, don’t wait until your weeds go to seed, because then there will be many more weeds next spring.

My Weed Warrior team estimates that, of the 20 or so invasive weeds on our Watch List, Blueweed and Spotted Knapweed are 80% of our region’s invasive weed problem. They are both tap-rooted plants, which means: you can use a digging tool like a screwdriver, to loosen the dirt so you can pull and garbage bag Blueweed and Spotted Knapweed.

Tap-rooted weeds can be pulled more easily from damp soil. So, try to schedule your weed pull after it rains, or use your sprinkler to dampen the weed patch for a couple of hours before you tackle it. For really big weeds, a mattock, a hoe, or the claw of a framing hammer can be used to dig up the taproot. A framing hammer can also pull mature “woody” knapweed stems from the ground like you would pull a nail from a wooden board.

Remember to wear protective gloves when handling invasive weeds, especially Blueweed- whose spiny stem hairs can give you an allergic rash. A neighbourhood weed pull is a great excuse for a potluck BBQ afterwards. Next week, I will write about broadleaf herbicides.