What Is Vinca Ground Cover?

Vincas flower in the spring.

Common plant names can be misleading and a prime example is the confusion between the annual flower called vinca and the ground cover vincas. The annual vinca (Catharanthus roseus), also called Madagascar periwinkle, is an easy-to-grow, sun- and heat-loving bedding plant sold in garden centers in spring. Ground cover vincas (Vinca spp.), on the other hand, are evergreen vines used under shrubs and as a lawn substitute in shady areas.

Vinca Minor

The smaller of the two ground covers, Vinca minor, is called myrtle, common periwinkle or just plain vinca. It has small, glossy green leaves and blue, lavender or white flowers in early spring, with sporadic reblooming throughout the growing season. It's hardy in U.S. Department of Agriculture zones 3 through 8, but may suffer browning from harsh winter winds in the colder parts of its range. This aggressive spreader performs best in partial to full shade, in rich, well-drained soil, and makes a good living mulch under shrubs and trees. Periwinkle is available in garden centers in flats in spring and fall. Plant the small plugs on 1-foot centers and mulch the first year or two to keep down weeds until the plants fill their space.

Vinca Major

Big-leaf periwinkle (V. major) is, as the name suggests, common periwinkle's big brother. It grows 8 to 18 inches tall, compared to periwinkle's 6 inches and both the leaves and flowers are larger. Big-leaf periwinkle is suitable for zones 6 to 9, so it's not as cold hardy but does tolerate the heat and humidity of the South and Southwest better than V. minor. Grow big-leaf periwinkle in the same shady, well-drained locations as the smaller vinca. A green-and-white cultivar, Variegata (also labeled as Elegantissima) is commonly sold in pots for use in mixed container gardens.

Common Cultivars

There are several different varieties of V. minor offered. Alba has white flowers and Atropurpurea has reddish-violet blooms. Bowles is a very commonly seen cultivar with slightly larger foliage (though not as large as V. major), a mounding habit instead of creeping and intensely blue or purple flowers that are slightly larger than the flowers of the parent species. To brighten up dark corners, plant Ralph Shugert, a variegated cultivar with white margins on the leaves and purplish-blue flowers.

Liabilities

Both vincas are easy to grow and rarely bothered by pests or diseases if properly sited. Too much sun burns the leaves and causes the plant to decline. If drainage is poor, vincas are subject to root rot and a stem blight that causes individual stems to die out; infected stems should be removed and discarded. The main problem with vinca is also one of its virtues: its aggressiveness. When happy with its location, vinca spreads to the point of invasiveness and will clamber over surrounding plants. It's best to use vinca under shrubs or in a bed by itself where its exuberant growth can be easily contained; unlike ivy, it won't climb up into shrubs or trees.

References

• Ohio State University Extension: Vinca Minor
• North Carolina State University; Vinca Major; Erv Evans
• Iowa State University Extension; Annual Vinca and Common Periwinkle; Jennifer Hoyer; May 2001