How to Grow and Care for Greater Periwinkle

Greater Periwinkle, known as Vinca major, is a fast-spreading groundcover valued for its vigorous growth. It presents a dense mat of glossy, evergreen leaves that remain year-round in many climates. Throughout the spring, the plant produces an abundance of violet-blue, phlox-like flowers, with some blooms appearing sporadically into the summer and fall. Its ability to flourish in a wide range of conditions allows it to establish quickly in many garden settings.

Planting Greater Periwinkle

The ideal times to plant Greater Periwinkle are in the spring or fall, allowing the root system to establish during milder temperatures. Its rapid, mat-forming growth makes it useful for controlling soil erosion on slopes and banks.

Prepare the soil by digging a hole that is as deep as the nursery container and twice as wide. Space individual plants about 12 to 18 inches apart to encourage a dense groundcover. After placing the plant in the hole, backfill with soil and water thoroughly to settle the roots.

Essential Care Requirements

Light

Greater Periwinkle is highly adaptable to different light levels, growing well in conditions ranging from full sun to heavy shade. In areas with intense summer heat, the plant benefits from partial shade, which helps keep the foliage a richer, darker green. Conversely, providing more sunlight encourages greater flower production.

Soil

This plant is not particular about soil and can tolerate poor or average conditions, including both acidic and alkaline soils. It performs best in moderately fertile, humus-rich soil that offers good drainage. If you have heavy clay soil, amending it with organic material can prevent water from pooling around the roots.

Water

Once established, Greater Periwinkle is drought-tolerant, requiring minimal supplemental water. During its first growing season, consistent moisture helps develop a strong root system. Water the plants regularly after planting, allowing the soil to dry out slightly between waterings. In extremely dry periods, occasional watering will help maintain vigorous growth.

Temperature and Humidity

This hardy perennial is evergreen in USDA hardiness zones 7 through 9. In colder climates, such as zone 6, it may experience foliage dieback during harsh winters but will regrow from the roots in the spring. A layer of mulch can help protect the roots in areas that experience frost.

Fertilizer

Greater Periwinkle does not require fertilizer and can grow aggressively without supplemental feeding. Applying a balanced fertilizer can sometimes stimulate excessive, leggy growth rather than promoting a compact habit or more flowers. For plants in containers, a light application of a balanced, slow-release fertilizer in the spring may be beneficial to replenish nutrients.

Managing Growth and Invasiveness

The vigorous growth that makes Vinca major a desirable groundcover also contributes to its potential for invasiveness. The plant spreads via long, trailing stems that root where they contact the soil, forming dense mats. This growth can overwhelm native vegetation if it escapes from garden beds into natural areas.

To maintain control, prune the plant hard once a year in late winter or early spring. This pruning rejuvenates the patch and contains its spread by cutting back wandering stems before they can root. Throughout the growing season, regularly trim the edges of the planting area to keep it within its intended boundaries.

Physical barriers are an effective method for containment.

• Install underground root barriers around the perimeter of the planting.
• Plant it in containers, window boxes, or raised beds to control its spread.
• Check with local authorities to determine if Vinca major is considered an invasive species in your region.
• Avoid planting it where it could escape into nearby woodlands.

Common Pests and Diseases

Greater Periwinkle is a resilient plant resistant to damage from deer and rabbits. It can, however, sometimes host pests like aphids and scale insects. These pests can be managed with applications of insecticidal soap if an infestation becomes noticeable.

The most common issues are fungal diseases such as leaf spot and root rot, which are a result of overly wet conditions and poor air circulation. These diseases can cause leaves to develop spots or the plant to wilt and die back. Ensuring the soil is well-drained and thinning dense patches to improve airflow are effective preventative measures. In many cases, improving the growing conditions will resolve these problems without fungicides.