Cryptostegia grandiflora, commonly known as Rubber Vine or Purple Allamanda, is a tropical woody vine native to south-west Madagascar. It is a vigorous, fast-growing climber with glossy foliage and large funnel-shaped flowers ranging from pale pink to purple with deep maroon centers. Seeds germinate readily after exposure to moisture and warm temperatures.
Before sowing
Soaking in warm water required to break seed dormancy
Sowing
What to expect
Tips
Seeds need light to germinate, so sow on soil surface and lightly press without covering. Keep soil moist but not waterlogged. Provide bright light but avoid direct sunlight which can overheat and dry out soil. Roots of seedlings are twice as long as shoots. Fresh seeds have better viability than older seeds.
Sources: plantflowerseeds.com, treefrogseed.com, Monaco Nature Encyclopedia, Grokipedia, Wikipedia, Kew Science, CABI Compendium
