Originally Posted by aruzinsky

Roundup is not synonymous with glyphosate because there are formulations of Roundup with additional active ingredients that can cause you real trouble. When you buy it, read the label to make sure that glyphosate is the only active ingredient.

You can try cutting the pseudostem at ground level and spooning out a hole, followed by pouring a tablespoon of the undiluted product into it and then covering with plastic wrap to keep the rain out. The advantage of using glyphosate is that it won't poison your soil for a long time.