Woody species, such as gray dogwood and sumac, are invading prairies. In this case, staghorn sumac has invaded an area with conservative prairie sedges. If the staghorn sumac is not controlled, the prairie species will die from excessive shade.

Placing flags is how I treat every stem that I have cut or frilled. I cut or frill 50 stems, apply herbicide, and then repeat. Before I began using flags to mark stems, I was only able to relocate about 90 percent of stems I had cut or frilled. Using flags to mark stems allows me to relocate all cut and frilled stems. The staffs of the flags shown above are not inserted into the ground because it was frozen.

The above is a frilled stem after 26 percent active ingredient glyphosate has been applied with a paintbrush. The frill was created by making cuts around the stem with a chisel.