One of my nemeses in our prairie is Crown Vetch (Securigera varia). It’s one of those beautiful/horrible weeds. I’m not sure how it got introduced — could be courtesy of some passing bird or the overflow of Northland Creek. For the past few years, there have been only a few invaders which I’ve pulled with no lasting effect. So now it’s to the point where I’m going to have to deal with it sternly or I’m not going to be able to get it under control.
In researching the solution to this problem, I’ve become aware of a herbicide called Milestone which seems to be most effective against Crown Vetch. It was developed by Dow primarily for use in rangelands, permanent pastures, rights-of-way and on CRP land, and is primarily used against some broadleaf weeds.
On pages 7-10 of Dow’s guide entitled “Invasive Plant Management with Milestone and Other Herbicides” there is a list of target weeds and Milestone application rates for their control and on pages 11-14, there is a list of some native plants and their degrees of sensitivity or tolerance to Milestone.
In reviewing the Milestone product label, Joy Perry wrote “Milestone is systemic within sprayed plants, so is eaten by livestock, wildlife or other grazers. The manure and urine of those grazers can damage sensitive plants. It will be present in hay made from sprayed plants. Sprayed plants can’t be used as mulch. Milestone persists in compost, so sprayed plants can’t be composted.”
According to the article “Long-term Control of Crown Vetch at a Wisconsin Wildlife Refuge” by Celestine Duncan, Mark Renz PhD of the University of Wisconsin Agronomy Department has found that late summer and fall application seems to be most effective.
If you’re interested, Renz and Panke have published a complete series on invasive plants entitled Management of Invasive Plants in Wisconsin which can be purchased in its entirety or viewed as individual pdfs from the UW-Extension’s the Learning Store.
Although carefully, so I paint only the Crown Vetch plants, it looks like I’ll be tackling eradication of Crown Vetch sometime during the next few weeks. Wish me luck!
Thank you Bob Niendorf and Joy Perry for your insight in hopefully eradicating the Crown Vetch invading my prairie.