Creeping Charlie, Glechoma hederacea is a perennial weed in the mint family that spreads by seeds, rhizomes and creeping stems that root at the nodes. It is a European native that was imported by early settlers because it is a good ground cover in shade. Anyone who has dealt with this would attest to the fact that it is a good, persistent ground cover, albeit not one that they prefer.
Creeping Charlie has bright green round shaped leaves with scalloped edges, opposite each other on a square stem. In the spring it produces small, pretty purple funnel-shaped flowers. When stepped on, it emits a very strong minty odor. In truth, it is a very attractive plant. If it weren’t so aggressive and didn’t have a tendency to show up in unwanted places, more people would appreciate it. In addition, once it welcomes itself into a garden, it has a tendency to not want to leave graciously.
This plant likes shade and moist conditions. Under trees and shrubs are ideal conditions for it to begin growing and it will continue to spread and dominate the landscape. Therefore, the first step in controlling Creeping Charlie is to alter the growing conditions of an established infestation. Improve light by trimming trees or shrubs; improve soil drainage or do not water as frequently. If the area of infestation is turf, work to improve the density and health of the grass. Do this by mowing to a height of 2 ½ to 3 ½ inches, do not take off more than ⅓ of the grass blade at any mowing, fertilize appropriately, and overseed if necessary. Alternately, if the area is too shady to sustain a good stand of grass, remove it completely and plant shade loving plants such as hostas, native pachysandra (Pachysandra procumbens), or ferns. Take care not to use plants in the invasive category such as Periwinkle (Vinca minor) or English ivy (Hedera helix) and thereby trade one problem for another.
The next step in controlling Creeping Charlie is removal of plants. The first thing to keep in mind is that it will take more than one season to be successful. Do not be discouraged if plants reappear after removal efforts. Just be diligent and persistent.
If attacking Creeping Charlie in a bed or border, the herbicides needed will not only kill the invader, but will also kill desirable plants. Therefore, hand removal is a better option. Use a hand weeder, ground rake, or simply pull by hand. Be aware that this plant will regenerate from small bits left in the ground so go back again and again to remove all parts. After weeding, add 2 to 3 inches of wood chips or good quality mulch to help smother any residual parts.
If the infestation is in turf and is in a small area, hand removal is an option. However, if a larger area is involved, apply a broadleaf herbicide containing salt of dicamba (3, 6-dichloro-o-anisic acid) or triclopyr (or just check the label to see if it kills Creeping Charlie). Always read and follow label directions carefully. The ideal time of application is mid-to-late fall after the first frost. At this point the plant is sending food reserves to the roots and will transmit the herbicide as well. If you are really determined to kill Creeping Charlie, reapply the herbicide in the spring when the plant is flowering (April to June).
If there is more Creeping Charlie than grass, it may be time to start over, kill all vegetation with glycophosphate (Roundup), and reseed the grass.
Borax has been promoted as an organic control. However, research at Wisconsin and Iowa universities has proven that it is not only ineffective, but it will harm surrounding plants.
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