Killing a Butterfly bush

Asked May 14, 2018, 6:56 PM EDT

How do you kill a Butterfly Bush? Is there a company around Corvallis who can accomplish this feat?

Benton County Oregon

1 Response

Thanks for your question.

Killing a butterfly bush mostly requires diligence. You can do it yourself. If you don't want to do it, you could call any of the arborists or yardwork providiers around town and ask them to deal with it. If you want to try, here's a guide:

Do not spray bush with a brush-control herbicide. It won't kill the plant, it will just slow it down.

What you need to do is:

1 Cut off all the branches. Do not leave them on the ground since they can form roots and re-grow. Never discard any part of this plant in natural areas or on roadsides. Put the branches in your yard waste container, or taken to a landfill or composting facility. If you in a rural area, you can burn them. Don't put them in your home compost pile.

2. Cut the trunk off at the base, but not at ground level, since you may have to make later cuts. I'd leave about six inches about the ground.

3. Immediately after you make the cut, apply concentrated glyphosate (such as Roundup) or triclopyr (such as Garlon or Brush B Gon) to the freshly cut surface. Either glysophate OR triclopyr, not both. More is not better.
Always follow the label directions on any herbicide product you use to minimize any potential risks to you and the environment. Follow all applicable laws and regulations regarding herbicide use on your site.
The glyphosate or triclopyr is taken down into the plant roots and severely damages the roots, If the plant is not old and well-established, one application should kill it. Otherwise, see step 4 & 5.

4. If the bush resprouts, it's absolutely essentially that you don't allow it to get going again. If it does, you will waste all your work.

5. Make a new cut on the trunk, below your first cut, and paint that with the glyphosate or triclopyr. Don't put glysophate or triclopyr on first cut again, since it will not be taken up as well as it is on a fresh cut. If it resprouts again, cut and reapply again.

You will kill the butterfly plant doing this. You may be able to kill it with one application of glysophate or triclopryr. But if the plant is old, it might resprout. You'll have to be diligent.

The problem you will still have is the seeds, which you probably already know about. A single flower spike can produce 40,000 seeds. Seeds can sprout for 3 to 5 years after they are produced. Make sure you pull up all the seedlings you find. They can go in the yard waste container or in the trash, but don't put them on your compost pile.

I hope this helps. If you have any questions, don't hesitate to contact Ask An Expert again.