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 nonselective 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.
Q: I plant my tomatoes, cukes and squash in pots on my deck. I’ve cleaned them and gotten rid of all the roots. Can I reuse the soil? Kitty Peschell, email