ajuga

Ajuga (Ajuga reptans)

Bugleweed, Carpet Bugle

Full sun to full shade, medium to moderately wet moisture, tolerates clay soils and compacted sites; pH 5.5–7.0; more vigorous in part shade with consistent moisture.

4–6 inches tall; blooms in spring (April–May in Middle Tennessee) with upright spikes of blue to violet flowers above dense rosettes of dark green, bronze, or purple foliage; spreads rapidly by stolons to form a dense carpet; can become invasive in lawn edges and garden borders.

Native region: Not native to Tennessee; ornamental introduction from Europe and southwestern Asia.

Ajuga is a common groundcover in Middle Tennessee landscapes and one of the few that tolerates the combination of deep shade and clay soil. Crown rot caused by Sclerotinia and Rhizoctonia can devastate dense plantings during the humid Middle Tennessee summer, particularly in poorly drained areas — this is the most serious cultural problem with ajuga in Zone 7. 'Chocolate Chip' and 'Black Scallop' are compact cultivars less susceptible to crown rot than older large-leafed types. At lawn edges, ajuga aggressively invades fescue stands via stolons; a defined edge or root barrier prevents this. Despite the invasive tendency, ajuga does suppress some lawn weeds through shading in areas where turf establishment is impractical.