Scientific: Asclepias curassavica (Synonyms: Asclepias aurantiaca, Asclepias bicolor, Asclepias cubensis, Asclepias margaritacea, Asclepias nivea var. curassavica)
Common: tropical milkweed, blood flower, Mexican butterflyweed, scarlet milkweed, matal, hierba de la cucaracha
Family: Asclepiadaceae
Origin: Tropical regions of North and South America, broadly naturalized globally across tropical and sub-tropical regions.
Invasive Alert: Tropical milkweed is invasive across many tropical and subtropical regions of the Americas, Australia and Asia, as well as in China, South East Asia and the Pacific.
Pronounciation: A-SCLE-pee-us cur-as-sa-VEE-ka
Hardiness zones
Sunset 12-24 (elsewhere as summer annual
USDA 9-11 (elsewhere as summer annual)
Landscape Use: Seasonal accent plant for mesic and tropical landscape themes, pollinator gardens.
Form & Character: Erect, stiff, open, airy, warm, cheerful, tropical, tender, informal.
Growth Habit: Evergreen, mostly herbaceous, perennial subshrub with a moderate, upright growth rate to 4-feet tall with less than equal spread. If it's irrigated regularly it will respond with increased vigor and size.
Foliage/Texture: Elongated, medium green, lanceolate leaves to 3-inches long with a prominent mid-vein, nearly sessile, opposite; medium texture.
Flowers & Fruits: Small, terminal yellow, orange to red flowers forming flat-topped umbels during spring through fall. Fruits are horn-shaped follicles to 3-inches long, seeds hairy.
Seasonal Color: Colorful flower accent during growing season, most intense in spring.
Temperature: Very heat tolerant, cold tolerant to 28oF.
Light: Full sun, but in Phoenix needs protection from summer western sun.
Soil: Tolerant.
Watering: Requires regular supplemental irrigation in lower desert gardens.
Pruning: Head back moderately to rejuvenate every 2 to 3 years.
Propagation: Seed, stem cuttings.
Disease and Pests: Aphids
Additional comments: Tropical Milkweed is great for Phoenix habitat and pollinator gardens. It attracts hummingbirds, butterflies and bees, and in particular is a forage source for the monarch and striated queen butterflies. Notable tropical milkweed cultivars include 'Red Butterfly' and 'Silky Gold'.
Poison alert: Tropical milkweed is poisonus to humans, dogs, cats, and livestock. So people, DO NOT ever use tropical milkweed as a salad garnish.
Minor taxonomic factoid: The genus Asclepias is named after the greek god Asklepios, the ancient god of medicine.
