Hardiness zones
Sunset All (short lived perennial in Phoenix that is mostly used as a summer annual)
USDA All

Landscape Use: Summer and fall flower beds, edging, color accent in hot climate

Form & Character: Perennial herb, evergreen in areas not experiencing freezes.

Growth Habit: Somewhat dependent on varietal series, 4" to 24" tall

Foliage/texture: Medium green leaves are oblong to lanceolate to 1-2" long, glabrous, nearly sessile, midvein prominent, medium texture

Flowers & fruits: Flowers range from white to mauve, typically rose-pink, 1.5" across, flower tubes about 1" long

Seasonal color: Flowers in late spring through and fall

Temperature: Prefers hot weather, although will bloom through Thanksgiving and in mild weather. During winter cold, periwinkle growth slows significantly and foliage will yellow.

Light: Full to partial sun, limit western exposures.

Soil: Well drained with some organic matter, prone to chlorosis in sandy soil

Watering: Regular in desert during summer

Pruning: Shearing larger plants will encourage compact dense canopy

Propagation: Seed, self-sows readily if flowers are fertile.

Disease and pests: Root knot nematodes, Rhizoctonia root rot, white flies, sudden wilt caused by Spiroplasma citri. The vector transmitting this disease is a leaf hopper. Catharanthus roseus is an alternate disease host. Citrus is the primary disease host.

Additional comments: Has medicinal properties and is poisonous when eaten by cattle. Highly bred. New cultivars, new flower colors released each year. Most consistent summer color for high heat areas. Don't plant in areas with nematodes or Rhizoctonia. Vinblastine sulfate is an alkaloid extracted from Catharanthus, which has been very successful in the treatment of childhood Leukemia and Hodgkin disease. Leurocristine, another isolated alkaloid, is used in almost all combination chemotherapy regimens for cancer.