Creeping Charlie, scientifically known as Glechoma hederacea, is a low-growing plant commonly found invading lawns and gardens across North America. This plant, also called ground ivy, has a long history of use that predates its current status as a garden pest, leading to curiosity about its safety and edibility. Before contemplating consumption, it is necessary to understand how to positively identify this plant and be aware of the inherent risks associated with foraging. The potential for ingesting this plant is conditional and requires careful attention to preparation and quantity.
Proper Identification and Look-Alikes
Positive identification of Glechoma hederacea relies on recognizing several distinct physical characteristics, as misidentification can lead to consuming an incorrect or potentially harmful species. As a member of the mint family, Creeping Charlie possesses the characteristic square stem that can be easily felt by rolling the stalk between the fingers. The plant is a vigorous creeper, spreading by above-ground runners called stolons, which root at the nodes when they touch the soil.
The leaves are a defining feature, typically kidney-shaped or rounded with distinctly scalloped or bluntly toothed edges, usually growing in opposite pairs along the stem. When crushed, the foliage releases a strong, distinctly minty, and sometimes pungent aroma. In spring, the plant produces small, funnel-shaped flowers that are usually light blue to bluish-purple, emerging from the leaf axils.
Several other common weeds can be mistaken for Creeping Charlie, making careful examination necessary for safe foraging. Henbit (Lamium amplexicaule) and Purple Dead Nettle (Lamium purpureum) are two common look-alikes that are also in the mint family and share the square stem feature. Unlike Creeping Charlie, however, the upper leaves of Henbit lack the small leaf stalk, or petiole, and appear to clasp the stem directly. Purple Dead Nettle grows more upright than Creeping Charlie’s prostrate habit, and its upper leaves often exhibit a purplish tint.
Edibility Status and Safety Concerns
Creeping Charlie is edible, but its consumption comes with significant cautionary notes, mainly due to its potent chemical composition. The plant contains a variety of compounds, including tannins and volatile oils such as pulegone and limonene. It is the presence of these volatile oils that gives the plant its strong aroma and contributes to its intense, peppery, and often bitter flavor.
The oil pulegone is recognized as a potential irritant and liver toxin when consumed in excessive amounts. For this reason, moderation is advised, and the plant should not be consumed in large, regular quantities. The tannins and bitter compounds can also cause gastrointestinal upset if the plant is eaten raw or in large helpings, leading to symptoms like stomach discomfort or nausea.
A major safety consideration is the plant’s known toxicity to livestock, particularly horses. Ingesting large amounts of Glechoma hederacea can lead to equine poisoning, characterized by excessive salivation, sweating, and difficulty breathing. This animal toxicity serves as a strong indicator that the plant should be consumed only sparingly. Proper preparation, such as drying or cooking, can help to reduce some of the more irritating volatile compounds and lessen the plant’s strong bitterness.
Traditional Uses and Modern Preparation Methods
Historically, Creeping Charlie held a much higher status than its modern reputation as a troublesome weed suggests, having been intentionally brought to North America by European settlers for its perceived value. It was widely used in folk medicine as a tonic and a remedy for various conditions, including congestion, kidney issues, and indigestion. Its high vitamin C content also made it a valuable resource for preventing scurvy during long voyages.
Perhaps its most notable traditional use was in brewing, where the plant earned the nickname “alehoof.” Before hops became the standard bittering and preserving agent, Creeping Charlie was added to beer to clarify the liquid and impart a pleasant, slightly bitter flavor. This use highlights its strong aromatic properties and its ability to influence the taste of beverages.
For modern consumption, the youngest leaves and shoots are preferred because their flavor is less intense than that of mature foliage. These young leaves can be added sparingly to fresh salads, acting more as a seasoning than a main green. The most common and safe method of preparation is drying the leaves and stems to make an herbal tea, which is less concentrated in volatile oils than the fresh plant. Alternatively, the leaves can be cooked like any other pot herb to mellow the bitter taste. It is crucial to harvest Creeping Charlie only from areas that are confirmed to be free of herbicides, pesticides, and animal waste.