Catharanthus are bushy perennials that are usually grown as half hardy annuals by gardeners.
They are also known by the names of Annual vinca or Madagascar periwinkle.
They reach about 30 to 60cm in height and have flat flowers of white or pink. They make good plants for growing in borders or as container plants.
Some of the latin names for Vinca plants and similar include catharanthus roseus, vinca difformis, v. major variegata, v. minor alba and v. minor periwinkle.
Vinca flower from the Summer on to the first frost of late autumn.
Common Names: Vinca Rose, Annual Vinca, Sadapphuli, Madagascar Periwinkle, Rose Periwinkle.
Life Cycle: Hardy perennial usually grown as a hardy annual by gardeners.
Height: 6 to 12 inches (15 to 30 cm).
Native: Madagascar, India.
Growing Region: Annual: zones 1 to 10. As a perennial in zones 9 and 10.
Flowers: Summer and autumn.
Flower Details: Pink, purple, white. Scented. Flat.
Foliage: Green. Glossy.
Sow Outdoors: 1/4 inch (6mm). Late winter (in warm areas only). Spacing 8 to 10 inches (20 to 25 cm).
Sow Indoors: Start indoors unless you live in a warm climate. Germination time: two to three weeks. Temperature 70 to 75°F (21 to 24°C). Start 12 to 15 weeks in advance. Transplant outdoors a few weeks after the last frost when temperatures do not drop below 40°F (5°C).
Requirements: Full sunlight or light shade. Soil pH 6 to 7. Moist soil. Light spring feed. Regular watering. If growing as a perennial occasionally cut back. Propagate by taking cuttings.
If planning to grow vinca plants outdoors then they should be sown in late winter at a depth of 7mm. They prefer to grow in moist soils with a pH of 6 to 7 in partially shaded or sunny areas of the garden. If you plan to grow Catharanthus indoors then they should be germinated in the dark with a temperature of 21 to 24 degrees Celsius; this takes from two to three weeks. Catharanthus seedlings should be allowed to grow for about 15 weeks before you plant them outdoors in mid-spring about 20 to 25cm apart.
The Annual vinca plants will require a light application of fertiliser in the spring and regular watering. If you require more plants then allow them to self seed, or you may prefer to take cuttings.