Calotropis gigantea var. white, commonly known as crown flower or giant milkweed, is a large tropical shrub native to Southeast Asia, prized for its stunning white waxy flowers arranged in umbrella-like clusters. This fast-growing milkweed family member is drought-tolerant and serves as an essential host plant for monarch and other butterfly species. Seeds germinate readily within 10-60 days when provided warm temperatures and proper pre-treatment.
Before sowing
Remove pod debris, scarify seeds mechanically, then soak in warm water for 24 hours before planting. Use a heated seedling mat to maintain optimal temperature between 77-84°F (25-29°C)
Sowing
What to expect
Tips
Always remove remaining pod material and debris from seeds before treatment. Scarify mechanically using sandpaper or a knife to break dormancy. Maintain consistent moisture but avoid waterlogging to prevent root rot. Use a heated mat to maintain steady temperature of 77-84°F (25-29°C) for optimal germination. Light press seeds into soil surface; they prefer shallow planting. Seedlings emerge quickly and grow vigorously. Provide ample light once seedlings appear. Be cautious: the plant's white variety is toxic—handle with care and keep away from children and pets. Plants are extremely drought-tolerant once established but seedlings benefit from regular moisture. Excellent for overwintering in containers in annual zones. Can also propagate successfully from softwood stem cuttings using rooting hormone.
Sources: Calotropis gigantea research from PlantFlowerSeeds, Ferri Seeds, PlantVine, Propagate.One, PFAF Plant Database, and peer-reviewed germination studies
