Ajuga, Carpet Bugle, Bugleweed
Lushness, brief but showy flowering, and rapidly spreading, tight growth make ajuga one of the most useful ground covers for medium to light shade. This evergreen perennial is sometimes used as a grass substitute in small to medium-sized areas, especially on slopes. Because it is shallow rooted, it makes a satisfactory cover for small bulbs. It is also useful around shrubs, in shaded parking strips, in moist rock gardens, and in the front of mixed borders. Foliage of smaller varieties is about 2 inches tall; foliage of larger varieties is 3 or 4 inches tall.
From spring to early summer, bright blue or blue-purple flowers appear on spikes usually 4 to 6 inches above the foliage. Individual flowers are small, but the mass of spikes is striking.
Leaves are oval to roundish, 3 to 5 inches long, 2 to 4 inches wide, in tight, glossy rosettes. Bronze or variegated leaves of some varieties contrast interestingly with other foliage in the garden. Green ajugas redden at first frost.
Moist, rich soil and good drainage are necessary for healthy, long-lived ajuga. Inadequate drainage can lead to root rot. Ajuga needs air circulation and brightness—light shade, or medium to light shade in hotter, drier areas. Space plants 6 to 12 inches apart, a bit farther for the big varieties. Stepping stones aid in maintenance, as ajuga will tolerate little or no foot traffic.
Care is moderately easy. Brightness, air circulation, and good drainage minimize the likelihood of root rot, powdery mildew, and root-knot nematodes. Use appropriate sprays if necessary. Spikes may be clipped after flowering.
A. r. atropurpurea has brown foliage. So does ‘Giant Bronze’, whose leaves are larger and somewhat metallic. ‘Giant Green’, also large, has clear green leaves. Jungle Bronze’ and ‘Jungle Green’ are both large, particularly the latter, with 8 to 10-inch spikes. A. r. rubra has dark, purplish foliage. The leaves of A. r. variegate are edged and dappled with creamy yellow. Other varieties are occasionally offered at nurseries.
