This handsome selection holds bright red flowers against bright green leaves all summer long through the hottest weather.
Madagascar periwinkle is a semiwoody evergreen perennial, usually grown as an annual in the flower bed. In frostfree climates it develops a woody stem near the base and can get 2-3 ft (0.6-0.9 m) tall and spread out just as wide. As annuals, they are usually smaller and more prostrate. Madagascar periwinkle has opposite glossy leaves about 2-3 in (5.1-7.6 cm) long, borne on fairly rigid stems. The five petaled flowers are typically rose pink, but among the many cultivars are those with pink, red, purple and white flowers. The flowers are tubular, with a slender corolla tube about 1 in (2.5 cm) long that expands to about 1.5 in (3.8 cm) across. They are borne singly throughout most of the summer. Like other members of the dogbane family, the broken stem of Madagascar periwinkle exudes a milky latex sap.
Madagascar periwinkle makes a great bedding plant for hot sunny situations like highway medians and commercial plantings. This tropical species is grown as an annual in temperate climates where it rewards with non-stop flowers throughout the summer until first frost.
Many beautiful selections of this fine bedding plant are available. The Cooler series of cultivars are low growing compact plants with rounded, overlapping petals in a variety of pastels. The Carpet series includes selections that are just 3-4 in (7.6-10.2 cm) tall and spread out 2 ft (0.6 m); they are great for groundcovers. The Pretty series includes compact, multiflowered plants around 12 in (30.5 cm) tall. 'Morning Mist' has large white flowers with rose colored centers. 'Parasol' has the largest flowers of all - 2 in (5.1 cm) wide and white with pink centers on robust 2 ft (0.6 m) plants.
This periwinkle is native to Madagascar. It has escaped cultivation and naturalized in most of the tropical world where it often becomes a rampant weed. It is established in several areas in the southern U.S. Madagascar periwinkle is grown commercially for its medicinal uses in Australia, Africa, India and southern Europe.
Madagascar periwinkle does best in poor, well-drained soils. Flowering will suffer if soils are too fertile. Pinch back early in the season to encourage branching and a fuller plant. Madagascar periwinkle doesn't need deadheading - the flowers drop off when they finish blooming. Light: Full sun or partial shade. Moisture: Madagascar periwinkle should be watered moderately during the growing season, but it is relatively drought resistant once established. In fact, it is unusually drought resistant for an annual. Madagascar periwinkle is not at all tolerant of overwatering. Hardiness: USDA Zones 9 - 11. Non-stop summertime flowers and heat resistance make this rugged plant a good choice to grow as an annual in cooler Zones. Propagation: Madagascar periwinkle is usually grown from seed, but also can be rooted from cuttings taken in spring or summer. It will reseed itself if the soil is loose.
Madagascar periwinkle and coleus cascading over the side in this container planting.
Where not hardy, grow Madagascar periwinkle in a container or as an annual in the summer flower bed. It's great in porch planters and window boxes. It thrives in the heat of summer when true periwinkles have faded away. In frostfree regions this pretty little flower is grown in borders and beds, as an edging plant and as a ground cover. It's a great groundcover owing to its very glossy leaves and long period of bloom. Very tolerant of hot summers, Madagascar periwinkle is the southern and summertime replacement for true periwinkles. Its leaves may curl during hot, dry days, but they return to normal when temperatures drop and the dew falls in the evening.
This Madagascar periwinkle has the rose-pink flowers typical of the species.
The true periwinkles, genus Vinca, are also in the Apocynaceae and quite similar to Madagascar periwinkle, but they do not perform as well in the heat. Madagascar periwinkle is the best choice for a southern bedding plant. Even in northern zones Madagascar periwinkle is one of the most dependable summertime bedding plants for mass color.
Madagascar periwinkle contains a virtual cornucopia of toxic and useful alkaloids. The leaves were sometimes smoked for their narcotic (but dangerous) effects. The plant has been used for centuries to treat diabetes, high blood pressure, asthma, constipation and menstrual problems. More recently, extracts from Madagascar periwinkle have been shown to be effective in the treatment of various kinds of leukemia, skin cancer, lymph cancer, breast cancer and Hodgkin's disease. Indeed, Madagascar periwinkle is a modern day success story in the search for naturally occurring anticancer drugs.
Madagascar periwinkle is poisonous if ingested or smoked. It has caused poisoning in grazing animals. Even under a doctor's supervision for cancer treatment, products from Madagascar periwinkle produce undesirable side effects.