More About White Periwinkle...
White Periwinkle, 'Vinca minor' 'Alba', is a fast spreading evergreen groundcover with glossy, dark green foliage that is as attractive during winter as it is in summer. In early spring, the carpet of foliage becomes covered in pretty pure-white periwinkle flowers.
White Periwinkle is easy to grow in the right conditions. It will fill a space faster if grown in organic, moist, well-drained loamy soil, but it will also grow quite well in heavy clay as long as it gets adequate moisture. That being said, it will tolerate periods of dry weather. If the foliage begins to wilt during a long summer drought provide supplemental water. More flowers will be produced if the plants are growing in a spot that provides some morning sun or filtered light during the day. It will tolerate full sun in zones 3 to 6 but requires afternoon shade in zones 7-8. It must have all-day shade in zone 9.
White Periwinkle is great evergreen groundcover in shade gardens because deciduous plants like hosta lily, perennial ferns and others have no trouble popping right through it in spring. The vines are quite aggressive, and will quickly form a dense carpet, but do not climb, cover or choke out other plants in the garden.