Creeping Charlie (Glechoma hederacea), also known as Ground Ivy, is an invasive perennial plant that often colonizes lawns and gardens. Originally introduced to North America from Europe for its supposed medicinal and culinary properties, it is now recognized as a pervasive and aggressive weed that is difficult to eliminate. Homeowners often question whether this plant presents a genuine problem for the health of their vegetation and the safety of their household pets.
How to Identify Creeping Charlie
Creeping Charlie is a low-growing, evergreen member of the mint family (Lamiaceae). Its most distinguishing feature is its square-shaped stem, a trait common to all mint relatives. The plant spreads rapidly via horizontal stems, called stolons, which creep along the ground and root firmly at the nodes. Its leaves are typically kidney-shaped or round with distinctive scalloped edges, and when crushed, they release a strong, mint-like odor. In the spring, small, funnel-shaped flowers appear in clusters, usually displaying bluish-purple to violet colors.
Why It Is a Problem for Lawns and Gardens
The primary concern for most homeowners is the plant’s aggressive growth habit, which allows it to quickly overwhelm desirable vegetation. Creeping Charlie is highly adaptable, thriving particularly well in shady, moist areas where turfgrass is already struggling. Its ability to spread extensively via its stolons allows it to form dense, expansive mats that smother lawn grasses and garden plants by blocking sunlight and competing for soil moisture and nutrients. The plant also possesses an allelopathic quality, meaning it can produce biochemicals that may inhibit the growth of surrounding plants. This combination of aggressive vegetative spread and chemical warfare makes it extremely difficult for grass to survive in an infested area.
Potential Toxicity to Pets and Livestock
While Creeping Charlie is a serious threat to lawns, its danger to typical household pets is often overstated. The plant contains volatile oils, including pulegone, and bitter compounds, which cause its distinctive aroma and taste. For dogs and cats, ingestion is rare due to the bitter flavor, and if consumed, it usually results only in mild gastrointestinal upset. However, the plant is considered toxic to livestock, especially horses, when consumed in large quantities. Horses that eat significant amounts may exhibit clinical signs like excessive slobbering, sweating, and dilated pupils, and poisoning can lead to respiratory distress.
Control and Removal Methods
Eradicating Creeping Charlie requires a persistent, multi-faceted approach due to its waxy leaves and extensive root system. For small, isolated patches, hand-pulling can be effective, but the entire stolon and all associated root fragments must be removed to prevent re-sprouting. Improving lawn health is a preventative measure, involving proper soil drainage, increasing sunlight by pruning trees, and overseeding to increase grass density. For larger infestations, chemical control is necessary, but standard broadleaf herbicides are often ineffective due to the plant’s thick, waxy cuticle. Herbicides containing triclopyr or dicamba are recommended, and the most effective time to apply them is in the fall, after the first frost, when the plant is actively moving nutrients down to its roots.