A perennial in warmer climates, vinca (Vinca) is an annual is cooler growing zones. This shrub-like, flowering vine can resemble impatiens, but two species have a periwinkle flower and glossier leaves. Vincas thrive in partial shade with moderate watering, but will tolerate sun with heavy watering. The Vinca rosea species prefers full sun. These plants flower throughout the summer season and in all climates, and will survive the winter in warmer climates.
The larger of the vinca species, Vinca major is aggressive and invasive. These plants can grow to 2 feet with leaves that are up to 3 inches long and flowers up to 2 inches across. Vinca major thrives as a perennial in southern states and is an annual in northern states. The 1997 "Sunset National Garden Book" recommends cutting the plant to the ground every few months to encourage new growth. A variety with cream-colored leaves is also available.
A dwarf species, Vinca minor has smaller leaves and flowers than Vinca major, and grows to about 6 inches. Available in many varieties, including Sterling Silver, Bowles' Variety and Ralph Shugert, all have variation in the hue of the color and may have some white on the leaves. The Alba and Miss Jekyll varieties have white flowers. Also known as common periwinkle, these plants do well in the eastern half of the United States as well as Texas, Kansas, Nebraska, Arizona, Utah, Montana and Washington., according to the USDA Department of Natural Resources fact sheet.
Known as Madagascar periwinkle, Vinca rosea is available at major retailers in flats for summer plantings. This species has flowers ranging in color from white to pink to bright rose, as well as some bicolor flowers. Vinca rosea can grow to 2 feet, depending on the variety, and is also available as a vine. Available in many varieties, the Little variety grows to about 10 inches, the Pacific and Cooler varieties grow to 15 inches and the Tropicana is an early bloomer. Blooms come throughout the summer and into late fall, if the weather is mild. Vinca rosea thrives in full sun with moderate watering.