Creeping Charlie (Glechoma hederacea) is an aggressive perennial plant that many North American homeowners find difficult to manage. This Eurasian native was introduced by early settlers, who valued it for medicine and as a groundcover. Today, it is widely recognized as a persistent, invasive weed that rapidly spreads across turf and planted areas. Its ability to thrive where turfgrass struggles makes it a formidable opponent in the battle for a tidy landscape.
Identifying Creeping Charlie and Its Invasive Behavior
Recognizing Glechoma hederacea is the first step in management. The plant is characterized by bright, kidney-shaped or rounded leaves with scalloped edges, which often appear shiny or waxy. Like all members of the mint family (Lamiaceae), Creeping Charlie has square, four-sided stems. In the spring, small, trumpet-shaped flowers in shades of bluish-purple or lavender appear near the leaf axils.
Its invasive status stems from its highly effective reproduction method. Creeping Charlie utilizes above-ground runners, called stolons, which trail along the soil surface, sometimes reaching lengths of up to seven feet. New roots and shoots readily emerge from the nodes along these stolons whenever they contact the ground. This mechanism allows it to rapidly establish dense, low-growing mats. Even a small stem fragment left behind can quickly root and grow into a new plant.
Creeping Charlie thrives in moist, shaded environments, often with compacted or poorly drained soil, where traditional turfgrass struggles. This hardiness allows it to easily outcompete weakened grass, frequently invading poorly maintained lawns or areas under tree canopies. Furthermore, it is an evergreen creeper in many climates, continuing to spread even when other plants are dormant, giving it a significant head start each spring.
The Detrimental Impact on Lawns and Gardens
The aggressive spread of Creeping Charlie leads to a decline in the health of turf and garden beds. As the stolons root at every node, they form thick, dense mats that smother desirable lawn grasses and ornamentals. These mats block sunlight and steal water and nutrients from underlying plants, causing them to weaken and die.
The extensive network of shallow, fibrous roots makes manual removal difficult, especially across large areas. Since the plant quickly re-establishes from small stem fragments, incomplete hand-pulling or routine mowing can exacerbate the problem by scattering viable pieces. This transforms healthy turf into a patchy, uneven expanse of weed growth.
While generally safe for humans and pets, Creeping Charlie carries a mild toxicity risk for specific grazing animals. It is known to be toxic to horses if consumed in large quantities. This factor, combined with its ability to choke out beneficial vegetation, solidifies its designation as a nuisance weed.
Effective Strategies for Control and Eradication
Eradicating Creeping Charlie requires a persistent, multi-faceted approach combining cultural practices and targeted treatments.
Manual Removal
For small infestations, intensive manual removal can be effective, provided the entire root and stolon system is meticulously removed. Saturating the soil before pulling makes it easier to remove the shallow roots without breaking the stems. All pulled plant material should be bagged and disposed of, not composted, to prevent fragments from re-rooting elsewhere.
Cultural Controls
Improving turf density and changing environmental conditions are crucial cultural controls. Encouraging a healthy lawn is the best long-term defense. This involves raising the mowing height to at least two and a half to three inches, which shades the soil and strengthens the grass. Addressing soil compaction through aeration and improving drainage in overly wet areas will also make the environment less favorable for the weed.
Chemical Control
For larger, established infestations, chemical control using selective broadleaf herbicides is often necessary. The most effective products contain active ingredients such as triclopyr, dicamba, or a combination including 2,4-D; triclopyr is particularly noted for its efficacy. Because the plant’s waxy leaves resist absorption, adding a non-ionic surfactant to the spray mixture helps the chemical penetrate the foliage.
Timing the application is a significant factor. The best time to apply herbicides is in the mid-to-late fall, after the first frost, when the plant is actively transporting food reserves down to its roots for winter storage. This process effectively carries the systemic herbicide deep into the root structure. Complete eradication often requires multiple treatments over two or more years, sometimes including a second application in the spring when the plant is flowering.