Botanical name:

Catharanthus roseus

Common names:

Madagascar periwinkle

Zones:

Technically a tender perennial in Zones 9 to 11, but usually grown as an annual in most climates.

Height/spread:

Typically 12 to 24 inches tall and wide, with the exception of dwarf and trailing types.

Bloom time:

Early summer until frost.

Special features:

• Attracts butterflies.
• Heat and drought tolerant.
• Needs no deadheading.
• Attractive glossy green leaves.
• Rabbit resistant.
• Pest and disease resistant.

Note: Not to be confused with common periwinkle (Vinca minor) and greater periwinkle (Vinca major), which are low-growing, evergreen perennials often used as groundcovers.

Where to plant:

In full sun to part shade in well-drained soil.

When to plant:

After the ground has warmed up in the spring, typically mid-May or later in northern climates.

Growing in containers:

Plant in any general-purpose, well-draining potting soil. One with a slow-release fertilizer will keep your plants well fed for a month or longer and get them off to a vigorous start. If combining vincas in the same container with other annuals or perennials, choose varieties that have the same exposure and water requirements.

Planting in the garden:

Space plants far enough apart to ensure good air circulation (about 8 to 12 inches, depending on plant size at maturity). In heavy soils, work in some compost at planting time to improve aeration.

Watering:

Vincas like their soil to be on the dry side, so only water when the top inch or so of the soil feels dry to the touch or when rainfall is insufficient to supply an inch of water per week. To prevent leaf spot and fungal diseases, avoid overhead watering or water your plants early in the morning so the foliage has plenty of time to dry before nightfall.

Fertilizing:

Apply a light top dressing of compost or a slow-release granular fertilizer at planting time. Container-grown plants may need more frequent feedings with a liquid fertilizer.

Pruning:

Although pruning is unnecessary, you can pinch plants back if you want a fuller appearance. Flowers are self-cleaning, sparing you the chore of deadheading.

Pests and problems:

Annual vinca is invincible to most pests, but it can succumb to stem and root rot caused by Phytophthora—a soil- and water-borne fungal-like microorganism. The best preventive measures are to avoid overwatering and provide good drainage. These plants are also susceptible to leaf spot diseases, with the best defense being good air circulation and to water them in the morning. Another way to avoid fungal problems is to plant one of the newer disease-resistant cultivars, such as the Cora® series.

Information from www.gardendesign.com