Tectona grandis aka Teak

Tectona grandis, or teak, is a large tropical tree. It belongs to the mint family, Lamiaceae. Its native range runs from India to Indo-China. It grows in tropical forests that shed their leaves seasonally. People now plant teak across tropical and subtropical regions. They grow it for timber and as an ornamental tree. Demand for its wood has damaged many old native forests.

In gardens, teak reaches about 80 feet [24.38 metres] tall. Its crown can spread to 60 feet [18.29 metres]. Other accounts give heights of 98–131 feet [30–40 metres]. Wild trees may reach 150 feet [45.72 metres]. The crown is open, with many small branches. The trunk often has broad supports at its base. Its grey-brown bark has fibres and shallow cracks. Young twigs bear silver to rusty hairs. The tree grows fast and loses leaves in seasonal climates. Where seasons lack clear shifts, it keeps some foliage.

The large, oval leaves grow in pairs along the stems. They reach 1.5 feet [0.46 metres] long and have smooth edges. Their upper surface is green and feels soft. Silver hairs cover the lower surface. Small, scented white flowers appear from June to August. They form broad clusters at the tips of branches. Bees, flies and ants pollinate the flowers; butterflies also visit. Teak does not set seed through self-fertilisation. Round, woody drupes ripen in winter beneath green, spongy coverings.

Grow teak in full sun with moist, fertile, well-drained soil. It favours acidic, sandy soil but accepts other soil types. Warm conditions with distinct wet and dry seasons suit it best. Established trees withstand drought, though cultivation calls for moderate water. It grows outdoors in USDA zones 10–12 and cannot tolerate frost. Missouri Botanical Garden reports no major pest or disease problems. It serves as a shade tree in large gardens. People also use it as a lawn or street tree.

Teak wood resists water and lasts well in use. Builders use it for boats, furniture, veneers and outdoor structures. Leaves supply colour when cooks boil jackfruit for gudeg. They also help with soybean fermentation and wrap market foods. Leaves and root bark provide dyes for cloth and paper. Traditional medicine uses wood and root oil for several ailments. These reported uses do not establish safe or effective treatment. Fine wood dust can irritate skin and trigger breathing allergies.