Cassia Tree (Golden Shower) Growing and Care Guide

The cassia tree (Cassia fistula), Thailand's national tree and "golden shower" for its spectacular yellow cascades, combines ornamental beauty with medicinal heritage. This fast-growing deciduous tree reaches 10-20 meters with pinnate leaves and pendulous racemes of five-petaled flowers each spring.

Propagation from Seed

Cassia seeds have extremely hard coats requiring scarification. Commercial growers soak seeds in concentrated sulfuric acid for several hours (duration varies by species), then wash thoroughly and soak 24 hours before sowing. This breaks dormancy for reliable germination.

Planting and Establishment

Transplant at 6-leaf stage into holes accommodating the entire root ball. Ideal soil pH: 6.6-7.5 (neutral). Mix native soil with compost and peat moss. Create a water-retaining berm around the planting hole. Water lightly until established. Mulch young trees for frost protection.

Ongoing Care

• Light: Full sun required for true flower color and heavy blooming
• Water: As climate demands once established
• Fertilizer: Apply before flowering season for best display
• Pruning: Remove dead/diseased wood only
• Pests/Diseases: Highly resistant

Important Cautions

All tree parts contain toxic compounds—seeds are poisonous. Not safe for direct consumption despite medicinal uses. Best suited for public spaces rather than gardens with children or pets. The pungent fruit odor may be undesirable near living areas.