Periwinkle Flower Information

Start periwinkle plants in containers with draining holes.

Periwinkle---or vinca---flowers are popular among gardeners wanting to bestow purplish blue flowers on their landscape. Not only are their blossoms an attractive touch, but their foliage sets off the flowers and adds healthy color to yards. According to Colorado State University, periwinkle flowers can provide season-long focal points for containers and garden beds.

Name

Periwinkle plants go by various names such as Madagascar periwinkle, vinca and Catharanthus. This plant is a member of the dogbane family, which includes flowering vines that are often planted on trellises. Originally, periwinkle plants were known as Lochnera, but were then changed to Ammocallis before ending up as Catharanthus. In Latin, Catharanthus is known as pure flowers. Gardeners identify the plant by looking to see if they are single blossoms and not doubles, because the plant never flowers as a double blossom.

History

This flower has a long history that started in Asia. Gardeners have been growing periwinkle for centuries in Asia, Europe, India and the United States according to Colorado State University. Herbalists grow the plant for its presumed medicinal benefits for treating eye infections, diabetes, lung infections and sore throats and for lowering blood pressure. Popularity of vinca flowers and periwinkle skyrocketed after the 1980s when more cultivars were developed.

Growing Conditions

Periwinkle plants do not like cold or cool temperatures. Therefore, gardeners have the option of either waiting to late spring or starting their plants indoors. The soil pH range must be between 6.0 and 6.5 for the plant to absorb the soil's nutrients. When grown outside of their range, periwinkle plants may experience stunted growth, discoloration or poor health. Well-draining soil is equally important. Soil must be able to drain for the plant to avoid contracting a fungal disease. Clay or poor draining soils may be amended with compost and builders' sand or the gardener may constructed raised garden beds.

Planting

Most gardeners pick container grown periwinkle plants to grow, because they will establish quickly in the growing season. Planting periwinkle plants requires a tilled garden bed that is free of weeds and grass. Gardeners should dig holes that are twice the width of the plant's root ball and place the root ball at the same depth at which it was growing in the container from which it is being transplanted. Because periwinkles can reach heights of one and a half feet, give them at least 12 inches of space in between plants.

Maintenance

Mulching is an important part of maintenance. A four-inch layer of mulch such as pine bark should be spread around the planting bed to lock in moisture and reduce the weed population. Watering is not much of a problem for the plants. Gardeners may either give these plants one inch of water along with the rest of the garden or not water at all. Pruning spent blossoms is unnecessary. Periwinkle blossoms will fall to the ground when they are spent.

References

• Colorado State University: The Year of the Vinca