SPECIES: Ajuga reptans (aj-oo'ga rep'tanz). Native habitat: Europe.

FORM: Dense, mat-forming ground cover that forms stolons (a prostrate branch from the base of a plant that runs along the ground or just below the surface and takes root.

SIZE: 6-10 inches tall, spreads far and wide but easy to pull up because its small roots run near soil surface. Growth rate: medium to fast.

EXPOSURE: Sun to shade

LEAVES: Semi- to fully evergreen; various varieties run from green to purplish and burgundy. Some cultivars turn purplish-bronze in autumn.

VARIETIES: Alba, creamy white flowers with light green leaves. Metallica Crispa, blue flowers with crinkled dark purple leaves. Burgundy Glow, blue flowers with green, white and dark pink to purple leaves; needs sun protection. Rosea, pink flowers with green leaves. Rubra, rose flowers with dark purplish leaves. Silver Beauty, blue flowers with light grayish-green leaves with white edges. Silver Creeper, blue flowers with metallic gray leaves. Variegata, gray-green leaves with creamy-white markings. Multicolor, striking purple-and-golden foliage.

FLOWERS: Small spike-like flowers April-May.

CULTURE: Ajuga is sun tolerant but grows best in light shade. Needs well-drained but moist organic soil with a 6.5 pH or acidity level. Keep soil moist or mulched because ajuga roots are shallow rooted; not drought tolerant.

USES: Low-maintenance ground cover good for shaded areas, especially under trees where grass won't grow. Good rock garden plants.

PROBLEMS: Crown rot, root knot nematode, spider mites; hot, dry locations.