Ochroma pyramidale, commonly known as balsa tree, is a rapidly growing pioneer tree native to tropical rainforests from southern Mexico to Bolivia. Seeds exhibit physical dormancy with an impervious testa requiring heat treatment for successful germination.
Before sowing
Scarification
agua_quente Heat treatment with boiling water (98-100°C for 3-20 seconds) or soaking in water at 80°C followed by room temperature water. Seeds contain impervious testa that must be ruptured by heat.
Soak
24 h Soak seeds in room-temperature water for 24 hours to soften seed coat and improve germination rates.
Smoke / fire
In natural conditions, forest clearance exposes soil to sun and triggers germination. Under natural conditions, fire exposure breaks dormancy.
Pre-treated seeds show 65-75% germination. Freshly collected seeds have only 10% germination without treatment.
Sowing
Substrate
Sterilized soil, well-draining potting mix, porous substrate, sand
Depth
superficie
Temperature
30°C
Moisture
alta
Container
Nursery pots, containers, lines 3-4cm apart
What to expect
Step 1
Pre-treat the seed
Step 2
Sow at superficie · 30°C
Day 6–28
Seedlings emerge (~70%)
Tips
Seeds are light-sensitive and should be placed superficially. Seeds must be sown in sterilized soil under slight shade to prevent damping-off. Very small seeds can be stored for several years. Temperature around 70-80°F optimal. Keep soil moist but not waterlogged.
Sources: PFAF Plant Database, Tropical Plants Database, Scientific studies on Ochroma pyramidale germination
