Ochroma pyramidale aka Balsa

Ochroma pyramidale, or balsa tree, belongs to the mallow family, Malvaceae. Its native range runs from southern Mexico through tropical America. This includes parts of the Caribbean and South America. It grows in warm, wet lowlands, including forests on limestone. It also grows beside streams, around lakes, and on cleared ground. It is less frequent in older forest.

This fast-growing evergreen forms a broad crown with a flat top. Reported size reaches about 98 feet (30 metres) tall and wide. Exceptional trees reach 164 feet (50 metres) in height. The straight trunk is often short and round in section. It can measure about 3–6 feet (1–1.8 metres) across. Older trees form short buttresses at the base. Its rapid growth helps it take hold in forest clearings. People also plant it for shade and as an ornamental tree.

Bats and birds pollinate the flowers. The seedpods hold wool-like fibres around the small seeds. People have used this soft material to fill pillows and mattresses. Bark fibres have also served to make rope. The wood has a pale white to grey-white colour. Older wood may have a pink tint near the centre. Its grain runs straight, and its texture is coarse but even. Balsa supplies very light commercial timber, with uses that include model aircraft. It also helps restore native woodland and establish woodland gardens.

Grow this tree in full sun, with deep, fertile soil. The soil should hold moisture but drain well. It accepts sandy, loamy, and clay soils, including heavy clay. It prefers mildly acid soil but tolerates a wider pH range. Warm, humid conditions suit it best. Preferred daytime temperatures span about 18–35°C. It can endure some drought when the air stays humid. PFAF places it in USDA zones 10–12 and notes frost sensitivity. Dormant plants may survive temperatures near 5°C.

Seeds need heat to break their hard outer coat. Without treatment, fresh seed has a low germination rate. Nursery guidance calls for sterile soil to help prevent damping-off. The supplied sources name no other specific pests or diseases. PFAF lists no known food uses and gives no known hazards. That hazard statement does not establish safety for people or pets. The root bark has a recorded use to induce vomiting. This medicinal record is not evidence that home use is safe.