Vinca Perennials

Description

• Vinca perennials are low-growing, spreading plants. They grow to a maximum height of 4 to 6 inches and will spread unchecked if not controlled or pruned. Their evergreen leaves have a glossy finish. The flowers' colors vary depending on the cultivar, but most are a shade of lavender. The cultivar Alba features creamy white flowers, while Atropurpurea's flowers are so richly purple that they appear to be burgundy.

Culture

• Periwinkle plants grow well in U.S. Department of Agriculture hardiness zones 4 through 8, which run from Minnesota and Montana to Texas and Florida. These plants thrive in moist but well-draining soil and are adaptable to full shade, part shade or full sun. The plants grow best, however, if they get some protection from the afternoon sun, according to the University of Illinois Extension website.

Pests and Diseases

• This plant is hardy in that it does not usually suffer from serious insect pest problems, but it is prone to fungal diseases. Ironically, the same moist soil that gives the plant its vigorous growth also harbors fungi that can infect the plant. Overly waterlogged soil can lead to root rot, which destroys the roots and can kill the plant. Periwinkle is also prone to stem rot disease, another fungus that girdles the stems, cutting off the supply of nutrients to the rest of the plant. This causes parts of the plant to turn brown and die.

Other Considerations

• Periwinkle is prized for the fact that it is an evergreen groundcover that features spring blooms - a rarity in the plant world. It can be tricky to find the perfect location for it, however. Too much sun causes poor growth and yellowing of the leaves, according to Ohio State University's Extension website. Too much water in the soil, and the plant suffers from edema, which is an excess of water in the plant tissues that causes water-soaked lesions to form. Suitable alternates to this plant include evergreen vining groundcovers such as ivy (Hedera helix) or low-growing junipers like Juniperus horizontalis and J. procumbens.