Ajuga reptans aka Ajuga

Ajuga reptans is a low perennial in the mint family. Gardeners call it bugleweed or common bugle. Its native range spans Europe, northern Iran, and northwest Africa. It also grows wild in Britain and Ireland. Damp fields and woods form part of its natural habitat. Its leaves stay green through winter, though some plants lose them.

The plant sends out runners that root and form mats. Garden plants stand about 0.5–0.75 feet [0.15–0.23 metres] tall. Flower spikes can reach 0.83 feet [0.25 metres]. RHS gives a broader height band reaching 1.64 feet [0.5 metres]. Spread ranges from about 1–3.3 feet [0.3–1 metre]. The glossy green leaves cluster in rosettes near the ground. They have rounded teeth along their edges. Smaller leaves grow in pairs along the flower stalks. These stalks have four sides and a light coat of hairs.

Small blue to violet flowers crowd upright spikes above the leaves. Each flower has a lipped shape. The main bloom falls in late spring and early summer. Missouri Botanical Garden lists May through June. Bees visit the flowers, and the plant attracts other wildlife. Each flower can form four small brown nutlets. These oval fruits have pits across their surface. The leaves provide ground cover beyond the bloom season.

Bugleweed grows best in moist soil with good drainage. It suits partial shade and can grow in deep shade. It also takes sun where the soil stays moist. It tolerates some dryness, but dislikes wet, heavy ground. Clay, loam, and sand can all support it. It accepts acid, neutral, and alkaline soil. Sources place it in USDA zones 3–10 or 4–10A. RHS rates its cold hardiness as H7. It needs little upkeep, and gardeners can divide crowded patches.

Use it beneath trees, on banks, or in containers. It can cover shady ground where lawns struggle to grow. Dense mats suppress weeds, but they tolerate little foot traffic. Runners can invade lawns and nearby beds. UF/IFAS classes it as invasive and does not recommend planting it. Crown rot threatens plants in soggy soil or humid conditions. Powdery mildew and nematodes can also cause harm. PFAF lists leaves and young shoots as edible. It reports no known hazards, but also notes heart-active substances. The plant has a history of external use for wounds.