Fall sweet clover control

Folks may be bored hearing about sweet clover. I discussed it a lot this summer, but unfortunately, there is also a fall season. We find two types of fall sweet clover plants: 1) new plants arising from the seed bank; 2) resprouts from stems that had been cut.

The resprouts are especially insidious. At Black Earth Rettenmund Prairie, where we had some large sweet clover infestations, we used Stihl brush cutters with triangular blades to cut the plants. The idea was to cut them when they were in full bloom, with the hope that since they were biennials this would eliminate them. Unfortunately, a lot of the cut stems resprouted and are now flowering. The photo at the left shows a typical stem.

You can see the thick cut stem (dark brown), plus at least "four" new shoots. Although not shown, each of those shoots has a few flowers, which will likely go on to make seeds. Ughhh!

It seems that the theory about eliminating sweet clover by cutting has some flaws. In some previous years, we did not have this problem. Perhaps our timing was wrong this year? Or perhaps the cool, wet weather we had this summer has had an effect. Whatever, our work is obviously not done yet.

Fortunately, most of the sweet clover at Rettenmund Prairie was pulled rather than cut. Only where we had major infestations did we resort to cutting. This was described in detail in the post that is linked here.

So, at our volunteer work party last Sunday, before starting seed collecting we spent an hour and a half pulling sweet clover. And because many of these plants would go on to make seeds if left on the ground, we bagged them all and disposed of them off site. You do what you have to do!