Periwinkle Flower Information
Periwinkle (Catharanthus roseus) is an evergreen perennial in the dogbane family (Apocynaceae spp.) growing in U.S. Department of Agriculture plant hardiness zones 9 through 11 and grown as an annual elsewhere. It's also called Madagascar periwinkle in reference to its country of origin, although the plant is now naturalized in tropical regions around the world, including the some portions of the Southern U.S. In addition to a variety of ways to display it in the landscape, periwinkle can also be grown indoors.
Periwinkle has 2- to 3-inch-long, oval-shaped, dark green leaves that appear opposite on round, sturdy stems. The leaves have a glossy finish and are pinnate, meaning the veins branch out on either side from the central stem in a way that resembles a feather. Space plants at least 12 and up to 24 inches apart, and periwinkle will form a dense ground cover 2 to 3 feet tall with an equal spread.
From early spring through fall, periwinkle produces single, five-petaled flowers roughly 1 inch long and 1 1/2 inches wide. They range in color from deep pink to purple, red and white, depending on variety. The flowers may be small but their continuous blooming habit gets the plant noticed, especially during hot weather when many other plants are no longer flowering.
Periwinkle is also known by many other common names, including vinca, graveyard plant, old maid, bright eyes, church flower and ram goat rose. However, this plant should not be confused with lesser periwinkle (Vinca minor), a European evergreen species also known as creeping myrtle that's grown as a ground cover in USDA plant hardiness zones 3 through 8.
Periwinkle secretes a white milky latex sap when its stems are broken, which may cause a contact-allergic reaction in some people. Also, even though alkaloids from periwinkle are used in the pharmaceutical industry to produce chemotherapy drugs, the U.S. Food and Drug Administration has classified the plant as unsafe for human consumption. The plant is also known to be toxic to cats, dogs and horses.
Periwinkle will grow in well-drained, loamy, clay or sandy soil, but doesn’t care for highly fertile soil. In fact, the plant often fails if the soil contains too much organic matter. While periwinkle enjoys a full day of sun, it will also thrive in partial shade.
Unlike many annuals, periwinkle is remarkably resistant to drought and heat. The plant is susceptible, however, to root rot and Verticillium wilt, diseases usually brought on by overwatering. During the growing season, water moderately just to add moisture to the top 2 inches of soil during dry periods, and avoid giving the plant “wet feet.”
- Periwinkle is deer resistant.
- Deadheading is not necessary; the spent flowers simply drop off.
- It has a long bloom time.
- It's generally nonaggressive and noninvasive.
- Tolerates periods of drought and high heat.
- Rarely affected by pests.
Plant periwinkle in beds and borders around foundations and trees for a colorful ground cover. It can also be planted in containers, window boxes and hanging baskets, from which it will trail. The plant can be trained to sprawl over a garden wall or trellis.
Periwinkle pairs well with other annual or perennial flowers in beds or containers. Because of its low-growing status, it makes a full and colorful backdrop for various combinations of perennial flowers, shrubs and ornamental grasses.
Periwinkle can be grown indoors as a houseplant or brought indoors from the garden to overwinter. Just as the plant cannot survive excessive moisture in the ground, guard against overwatering it as a houseplant. Make sure it's in a planer with drainage holes. Also, place the plant on or near a window where it will receive a few hours of natural light each day.
Dainty apricot-colored flowers that morph into white at the edges and feature a red “eye” at the center describes Apricot Delight (Catharanthus roseus ‘Apricot Delight’). Like other periwinkles, this variety will bloom most of the year in USDA zones 9 through 11. Not only does this plant tolerate drought and heat, it can survive a light frost.
A popular “spiller” and trailing plant, Cora Cascade (Catharanthus roseus ‘Cora Cascade’) is a hybrid that delivers vibrant red, violet and deep pink flowers from spring through fall in USDA zones 11a through 12b. This cultivar is ideal for containers and hanging baskets.
Periwinkle plants in the Cora series are considered invasive in Texas, California, Hawaii and some parts of the Southern U.S.
Titan Icy Pink
Titan Icy Pink (Catharanthus roseus 'Titan Icy Pink') is a bicolor periwinkle that features light pink flowers with a deep pink “eye” at the center. Suitable for containers, beds and rock gardens in USDA zones 10 and 11, this variety has a mounding habit and larger blooms than other varieties in this series.
- Floridata: Catharanthus Roseus
- University of Florida: Catharanthus Roseus
- Lucid Central: Catharanthus Roseus (Madagascar Periwinkle)
- Cornell University: Catharanthus Roseus
- American Society for the Prevention of Cruelty to Animals: Periwinkle
- Ohio State University: Vinca Minor
- Proven Winners: Catharanthus Roseus ‘Cora Cascade’
- Lucas Greenhouses: Catharanthus Roseus 'Titan Icy Pink'
Karyn Maier is a seasoned columnist and feature writer. Since 1992, her work has appeared in Mother Earth News, The Herb Quarterly, Better Nutrition and in many other print and digital publications. She is also the author of five books, and is published in six languages.