Cassia fistula, commonly known as the golden shower tree or Indian laburnum, is a tropical flowering tree native to the Indian subcontinent and Southeast Asia, celebrated for its stunning pendulous clusters of bright yellow flowers. Seeds require pre-treatment to overcome physical dormancy caused by their hard, water-impermeable seed coat. With proper scarification and soaking techniques, germination rates can exceed 80% and seedlings typically emerge within 10-21 days under optimal warm conditions.
Before sowing
Mechanical scarification followed by 24-hour cold water soaking is the recommended standard treatment. Alternative: acid scarification for 2 minutes followed by hot water soaking at 100°C for 6 minutes can achieve up to 96% germination.
Sowing
What to expect
Tips
Ensure seeds are mature and dark brown before collection. Extract seeds with gloves as they can be toxic. Use full light and high humidity during germination but avoid waterlogging. Keep soil temperature between 25-30°C for best results. Seeds planted in summer germinate more readily due to longer daylight hours. If soaking, discard any seeds that do not swell after treatment. Germination can sometimes be slow and irregular, so maintain patience. Multiple flushes of germination may occur over extended periods.
Sources: Wikipedia, Gardening Know How, PFAF Plant Database, Plants Flowers Seeds, University of Florida IFAS, Sheffield's Seed Company, ResearchGate publications on Cassia germination studies, EarthOne, Australian Seed
