How to Care for Periwinkles

Grow periwinkle in well-draining soil with a pH between 6.0 and 8.0 and exposure to partial sunlight or full shade. Space plugs of periwinkle ground covers 12 to 18 inches apart to provide individual plants room to spread and grow. Periwinkles spaced 6 inches apart will cover the area in less than one year.

Irrigate the soil around periwinkles soon after planting using a soaker hose or trickle irrigation system. Keep the soil evenly moist at all times throughout the first growing season to help the plants become established. After the first season, water the soil when the top 2 to 3 inches appear dry.

Spread 2 to 3 inches of organic mulch such as shredded bark or pine needles around plants to help retain soil moisture and keep the roots cool. Mulching the soil also prevents weeds from infiltrating the area and competing with the periwinkle plants for soil moisture and nutrients. Inspect the area frequently for weeds and pull these out of the soil by hand until the plant spreads and covers the area.

Feed periwinkle 6 lbs. of a well-balanced, 10-10-10 fertilizer per 1,000 square feet in spring. Irrigate the soil heavily after fertilizing the plant to help release nutrients in the soil.

Shear periwinkle plants close to the ground to encourage branching and new growth. Sterilize the blades of your pruning equipment in bleach solution or rubbing alcohol to prevent the spread of disease.

Inspect periwinkle frequently for symptoms of fungal diseases including brown spots or patches on the leaves (leaf spots), swollen lesions on stems (cankers) or sudden wilt and die-back. Snip off infected parts of the plants to prevent spread and apply a registered fungicide if necessary. Adopt good cultural practices to reduce future outbreaks.