Common Name: Madagascar periwinkle
Type: Herbaceous perennial
Family: Apocynaceae
Native Range: Madagascar
Zone: 10 to 11
Height: 0.50 to 1.50 feet
Spread: 0.50 to 1.50 feet
Bloom Time: June to frost
Bloom Description: Rosy pink to red with mauve throats
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Annual
Flower: Showy
Tolerate: Rabbit, Drought, Dry Soil
Culture
Winter hardy to USDA Zones 10-11 where it grows as a woody based perennial. In the St. Louis area, it is best grown as an annual bedding plant in well-drained sandy loams in full sun to part shade. Needs regular moisture, but avoid overhead watering. Superior soil drainage is the key to growing this annual well. Start seeds indoors 12-16 weeks before last frost date. Set out seedlings or purchased starter plants in spring after last frost date. Thrives in hot and humid summer weather. Cuttings may be taken from plants in late summer for overwintering so as to provide a stock the following spring. Container plants may be overwintered indoors. May self-seed in optimum growing conditions.
Noteworthy Characteristics
Catharanthus roseus, commonly called periwinkle, Madagascar periwinkle or annual vinca, is an erect to spreading tender perennial in the dogbane family typically mounding 6-18” (less frequently to 24”) tall and as wide. It produces attractive bushy foliage that is covered by an often profuse bloom of phlox-like flowers from summer to frost. Best flowering is in summer. Tubular flowers have five flattened petal-like lobes and appear singly in the upper leaf axils. Species flowers are rosy-pink to red with mauve throats. However, species plants are seldom seen in commerce today, having been largely replaced by larger flowered cultivars, many of which are dwarf to compact plants that sometimes have overlapping petals. Cultivars expand the available color range to include pale pink, rose, hot pink, red, lilac, and white, often with contrasting darker throats/eyes. Oblong to ovate glossy green leaves (to 2” long). Synonymous with and formerly know as Vinca rosea.
Specific epithet means rose colored.
Problems
No serious insect or disease problems. Stem rot, leaf spot and aster yellows may occur. Watch for slugs and snails. For more information see: Problems Common to Many Indoor Plants
Uses
Annual ground cover, bedding, edging or containers. Some varieties make excellent houseplants.