With trailing, arching stems that root where they touch soil, these plants are useful as ground and bank covers. Shiny, dark green, oval to oblong leaves. Lavender-blue, five-petaled, pinwheel-shaped flowers appear in leaf joints in early spring. Plant the larger species and its selections 2212 ft. apart, dwarf kinds 112 ft. apart. When plantings mound up or are layered with old stems, shear or mow before new spring growth begins. Very soil tolerant. Compete successfully with surface tree roots. Deer don't care for periwinkles.
V. major. GREATER PERIWINKLE. Zones MS, LS, CS; USDA 7-9. The larger, more aggressive species. Leaves to 3 in. long, purple flowers to 2 in. across; mounds to 12 ft. high. Spreads rapidly and can be extremely invasive in sheltered, shady areas. 'Variegata', probably as common as the green form, has leaves strongly edged in white.
V. minor. COMMON PERIWINKLE, DWARF PERIWINKLE. Zones US, MS, LS, CS; USDA 6-9. Miniature version of V. major, with 34- to 1 34-in.-long leaves, flowers to 1 in. wide, and a height of just 46 in. More restrained, less likely to invade adjacent plantings. 'Atropurpurea', deep purple flowers, small leaves; 'Illumination', bright gold leaves edge in green, blue flowers; 'La Grave' ('Bowles' Variety'), deeper blue flowers, larger leaves; 'Ralph Shugert', white-edged leaves, blue flowers, repeat autumn bloom; and 'Sterling Silver', blue flowers, white-edged leaves speckled with pale green. White-flowered versions include V. m. alba and its smaller-growing, heavier-blooming selection 'Gertrude Jekyll' ('Miss Jekyll').