Germination temperature
Warm tropical conditions; sow in the warm season.
Tree growing guide
Sterculia foetida is a fast-starting tropical tree with large red seed pods and shiny black seeds. Lightly scarified and soaked, fresh seed germinates within a few weeks in warm weather.
Warm tropical conditions; sow in the warm season.
Cover with about 2 cm (3/4 in) of mix, roughly the seed's own length.
First seedlings after about 8 days; most within 35 days.
Seed is covered; young plants need full light.
Sand one side of the seed, then soak for 24 hours.
Sow in nursery bags, plant out as a sapling.
Use firm, undamaged black seeds and discard cracked or mouldy ones. Wild almond seed stores well when dry: at about 7-10% moisture it kept its germination for a year in a sealed container, but drying it much further cracks the seed coat and lets fungi in.
Recommended. In a Brazilian nursery trial, rubbing one side of each seed on coarse (no. 40) sandpaper for 3 minutes, or both sides without soaking, gave the best and fastest germination, about 60-70%. Just wear through the coat; do not cut into the seed.
Not needed. This is a tropical tree and needs no cold period.
Soak the scarified seed in clean water for 24 hours before sowing. Sow at once after soaking.
Sow in warm weather. In India, the hot season before the monsoon or the early monsoon suits it; in cooler climates keep the pots in a warm greenhouse. The trial results above came from an unheated greenhouse in tropical Recife, Brazil.
Lay the seed flat and cover it with about 2 cm (3/4 in) of mix, roughly its own length.
A free-draining mix of organic matter and sand; the Brazilian trial used one part organic material to two parts sand in polythene nursery bags of about 25 x 15 cm (10 x 6 in).
Keep the mix evenly moist but never waterlogged. Damaged or cracked seed rots quickly in wet mix.
No light is needed for the buried seed. Move seedlings into full light once they are up.
Scarified seed begins to germinate after about 8 days, with most seedlings up within 35 days. Unscarified seed is slower and less even.
Sowing directly into individual nursery bags avoids disturbing the taproot later.
Plant out when the sapling is sturdy, at the start of the rainy season in the tropics. Choose an open, sunny site with deep soil and room for a large tree; it grows to about 40 m (130 ft) with a broad crown of whorled, spreading branches.
Early growth is fairly rapid and then slows. Water young trees in dry spells; the species grows best where it has enough soil moisture.
Cause: cracked seed coats, often from over-drying, letting fungi in. Fix: store seed at moderate dryness in a sealed container and sort out cracked seed before sowing.
Cause: the hard seed coat. Fix: sand one side for about 3 minutes and soak for 24 hours before sowing.
Cause: caterpillars of Sylepta balteata, the main recorded pest in Indian nurseries. Fix: inspect seedlings often and remove or treat rolled leaves early.
Cause: too much shade. Fix: give full light; this tree does poorly under a canopy.
The flowers, and the leaves when crushed, have a strong unpleasant smell, which gives the tree its name foetida. Plant it away from windows and seating areas.
This is a large deciduous tree for parks, avenues and big gardens, not for small plots or near buildings.
Native from East Africa to northern Australia, it grows freely across tropical Asia, including India, Sri Lanka and Myanmar. It is not frost-hardy; in cool climates it can only be grown under glass.
The large red, woody pods split open when ripe to show the black seeds. Collect them promptly and dry them only moderately before storing.
Scarify, soak and sow wild almond seed in warm weather for quick-starting tree seedlings.
No. Unlike many tropical tree seeds, they tolerate drying: seed at about 7-10% moisture kept well for a year in a sealed container. Avoid drying them so far that the coats crack.
Rub one side of each seed on coarse sandpaper for about 3 minutes and soak it for 24 hours. In a nursery trial this gave about 70% germination, starting after about 8 days.
No. It becomes a very large tree, and its flowers smell strongly unpleasant. Plant it in a park, along a wide road or on a large property.