Garden Club reader J. F. Neely asks:
How do I control Creeping Charlie? Is there anything I can do at this time of year? If not when can I start treatment? Thanks for all your help!
For those not in the know, Creeping Charlie is one name for Glechoma hederacea, a low-down, shade-loving weed in the mint family. Anyone worried that naming a weed “Charlie” might give men a bad name can take consolation in knowing that it’s sometimes also called Creeping Jenny—not to be confused with Lysimachia nummularia, which goes by the same name. At the Garden Club, we just focus on the “creeping” part—which is what’s really bothering J.F anyway.
If you’ve caught the weed early on, it may be possible to simply pluck it out of your landscape. More extensive growth can by removed using a thatch rake, which can destroy the root structure of the weed, though be advised that doing so might damage the grass as well. Not that there aren’t benefits to dethatching your lawn. Some people even collect their Creeping Charlie and use it as a salad green. Reportedly, it has a peppery taste.
Once Creeping Charlie gets out of hand, though, it can be difficult to remove from your landscape. If you’re ready to move on to more drastic measures, look for a herbicide that, like Ortho Weed-B-Gon, contains 2,4-Dichlorophenoxyacetic acid, usually abbreviated 2,4-D. Naturally, you’ll want to forgo the Creeping Charlie salad once you’ve zapped the leaves with herbicide. Vinaigrette makes for a better dressing anyway.
For that matter, be careful when applying herbicides, as they can also kill other plants if misapplied. Creeping Charlie’s preference for shady areas makes it particularly tricky, since you can count on it growing close to the roots of the plants you want in your landscape. Make sure you carefully follow the instructions that come with your herbicide of choice, and if there’s any doubt, apply it only to the leaves of the offending plant, and in small enough doses that it won’t pool on the ground and soak down to the roots of more welcome plants.
As for timing, early autumn is probably best. You want to deal with the invaders when the weather is cool, but not cold, and there’s no precipitation in the forecast. That will minimize the odds of your herbicide making its way into the water supply via storm water runoff. Unless you happen to be in one of the warmer regions—say, USDA Zone 10 or higher—it’s probably already too cold for an herbicide treatment to do much good. Your best bet now is probably to wait until after the first thaw of spring.