How do I remove Crown Vetch from my meadow?

Question:

I have a one and a half acre meadow behind my house that is infested with Crown Vetch. I have been trying to control the vetch by mowing in late spring (before flowering) and late fall. In the summer we have been pulling and or weed whacking when we see them plants starting to flower. It is a big area to use herbicides and I don’t want to damage the trees but I have used some Triclopyr (or maybe it was glyphosate) on some big patches. I need a plan to get it under control and allow the native grasses and plants to come back. What we are doing seems to be keeping it at the same level with maybe some reduction but not much. 

Answer:

Jonathan Foster, Home Horticulture Outreach Professional

I’m sorry to hear about your battles with crown vetch! Unfortunately, as you no doubt know firsthand, it’s tough to eradicate once established.

First, let me pass along a couple of good resources I found for controlling it from reputable sources:

MN Dept of Agriculture

MO Dept of Conservation

You’ll see that, for better or worse, you’re already doing a couple of things correctly (i.e., good for you for the tactics you’ve employed so far, bad for you in that you’ve been doing them and are still struggling with the plant!) Keeping the vetch mowed to prevent seeding is a key component to long term control; otherwise, it’s just replenishing itself in the seed bank in your soil. And triclopyr and glyphosate are mentioned in the Missouri link as front-line options–but they do touch briefly on proper application, so you may find some tips there that can make your approach more effective. The success rates look pretty high with an effective technique, though this of course varies by individual site. A comprehensive recommendation strategy will most likely employ both mechanical (i.e. mowing) and chemical intervention.

It may be safer, easier, and more productive to find a ME-licensed pesticide applicator for administering herbicide to such a large area. They will be aware of current products, any wetland regulations you may be subject to due to the stream proximity, and may have better suggestions after evaluating conditions on-site. Regardless of who applies it, please read carefully and follow conscientiously all instructions on the label. More is not better, and safety is the first priority.

I wish you good luck and (otherwise) happy gardening.