Q: I want you to discuss horsetail. I bought some at a garden shop several years ago and made the mistake of planting in the open ground. No one warned me that it is invasive. I’ll never make that mistake again. Is there anything we can spray to kill it?
A: I have my horsetail rush, Equisetum hymale, corralled in a large ceramic container with no drain. I keep it watered in summer (it loves boggy soil) and it makes a nice vertical accent. You’re correct, it is one of the few native plants that is invasive. It is said to be eaten by wildlife, but in my neighborhood the rabbits and squirrels leave it alone. I can’t imagine a deer being hungry enough to chew through all of the abrasive silica in the stems.
The bamboo like stems are so distinctive that you might get the best control simply by patiently snapping it off at ground level whenever you see it. You’ll eventually starve it to death.