Getting Rid Of Chameleon Plant

Q: We have a small cabin by a stream. Our garden beds are six feet up from the stream bank. Two years ago, our gardens were infested with chameleon plant. I don’t know where it came from, but it takes over everything. I don’t want to totally dig up my beds because I have other plants in them. Is my only method to get rid of the chameleon plant to pull it up by hand? 

A: Normally I would say digging everything out and replacing the soil is best. But digging so close to the water will lead to erosion. I think the only way to kill chameleon plant, Houttuynia cordata, is to use a non-selective herbicide but I think the distance is a little too close to use regular glyphosate (Roundup, etc). The label says to avoid application near bodies of water. The active ingredient is not the problem, it is the additives that are sometimes used for spraying in a landscape. But there is a solution: look for glyphosate products labeled for use in aquatic environments (Rodeo, Shore-Klear, etc). They do not have the additives, but you need to mix in a “spreader-sticker” chemical (CideKick, Turbo etc) to be sure the herbicide is absorbed by the leaves. You might have to paint the herbicide onto the chameleon plants with a foam paintbrush to avoid hurting your other plants.