How can I eradicate Chameleon plant in my garden bed?
Question:
I just identified Chameleon plant in my small garden bed. I noticed it a couple of years ago and tried to stay on top of it, but this last year, it has completely taken over and is choking out the perennials. I wondered if you had suggestions for eradication? I am wondering if it would help to put down landscape fabric, maybe at least six inches of mulch or small rocks? I don’t plan on trying to save my perennials because I know that the weed is probably all through those roots. Any advice would be very appreciated!
Answer:
Jonathan Foster, Home Horticulture Outreach Professional
As you may know (since you are asking about it), chameleon plant (Houttuynia cordala) can be a problematic spreader and a difficult visitor to remove once it’s established. The plant spreads by underground rhizomes, so the non-chemical intervention will mean carefully digging down and removing all subsurface parts of the plant and then vigilantly watching for new sprouts emerging (it will regrow from any missed rhizomes or broken rhizomes that are overlooked). I typically steer gardeners away from landscape fabric under these circumstances because it gets very tattered, messy, and difficult to ever remove once organic material and plant root growth work on it for a few years. However, your mulch idea is an excellent one after getting out as much as you can first. Few plants can survive being deprived of the photosynthetic machinery of green leaves indefinitely, so if you stay on top of it after the initial effort you can outlast the plant but it may take a couple of seasons.
The chemical recommendation, as per this Ask Extension response, is to use glyphosate (Roundup), though I have seen anecdotal reports of Houttuynia showing some resistance to the pesticide. It may take multiple applications and will probably also require a vigilant few seasons, as with the physical removal. PLEASE NOTE, glyphosate is a nonselective treatment that will kill most plants it comes into contact with, so this may not be feasible for your garden bed, depending on what you have growing there. If you choose to go this route, please read carefully and follow conscientiously the instructions on the label, and take care only to expose the Houttuynia to the chemical, especially if (as you suspect) it’s intermixed with your perennials.
In either case, if you can locate which direction the Houttuynia entered the bed from, you might be able to install a vertical weed barrier, like garden bed edging material, to help prevent it getting back in and ruining your hard work removing it.
Good luck, and happy gardening.