Common Name: giant milkweed
Type: Broadleaf evergreen
Family: Apocynaceae
Native Range: Asia, tropical Africa
Zone: 11 to 12
Height: 8.00 to 15.00 feet
Spread: 8.00 to 15.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: Pale purple or white
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Hedge
Flower: Showy
Leaf: Evergreen
Attracts: Butterflies
Other: Winter Interest
Tolerate: Drought
Culture
Thrives in medium moisture, well-drained soils in full sun. Established plants tolerate drought, but best growth and flower production occur in soils with consistent and even moisture. Propagate by stem cuttings.
Noteworthy Characteristics
Calotropis gigantea, commonly called crown flower or giant milkweed, is a large shrub or small tree that is native to India, southern China, Malaysia and Indonesia, but has been extensively cultivated in tropical areas around the world. This milkweed family member typically grows to 8-15' tall. It is noted for its upright growth, milky sap, pale purple or white crown-like flowers, and white wooly shoots and leaves which mature to subglabrous. Flowers appear in clusters (umbellate cymes) throughout the year, but primarily in summer. Flowers (both white and purple) are commonly used in Hawaii for leis. Elliptic to oblong leaves (to 4-8" long) have cordate bases. Fruits infrequently form. This giant milkweed is an important larval plant for monarch butterflies.
Genus name comes from the Greek words kalos meaning beautiful and tropos meaning boat in reference to the flowers.
Specific epithet means unusually tall or large.
Problems
No serious insect or disease problems. Sap in eyes can cause severe inflammation. Sap is also an irritant to mucus membranes.
Uses
Where winter hardy, grow as a hedge or train as a small tree. Where not winter hardy, grow in containers which must be overwintered indoors.