Olea capensis aka Black Ironwood

Olea capensis is known as black ironwood or South African ironwood. It belongs to the olive family, Oleaceae. Its native range spans tropical and southern Africa, Comoros, and Madagascar. It grows in bushland, coastal scrub, and evergreen forest. In some woodlands, it forms a large share of the trees. It occurs in tropical and subtropical regions, including cool upland sites.

This evergreen plant forms a bushy shrub or small tree. Its usual height reaches about 33 feet [10 metres]. Exceptional trees can reach 131 feet [40 metres]. A cultivated tree shown by Useful Tropical Plants has a broad crown. Young plants can grow fast, but older trees grow much slower. Reported growth during the first four years averages 3.6 feet [1.1 metres] yearly. Its lasting foliage and woody form provide year-round structure.

Heavy flowering occurs late in the dry season, but not every year. The gap between large flower crops may reach seven years. Fruits need about six months to ripen after flowering. The ripe fruit is a fleshy, purple drupe with an egg-like shape. It can reach about 0.8 inches long and 0.4 inches wide. People sometimes eat the fruit. The supplied account lists no known hazards. This does not establish safety for every use or for pets.

Choose a sunny site with soil that drains well. The plant also tolerates some shade. It prefers soil with a pH between 5.5 and 7. It can tolerate a wider range, from 5 to 7.5. Its preferred climate has a clear dry season. Annual rainfall of 800–1,200 millimetres suits it best. Preferred mean annual temperatures fall between 14 and 18°C. These climate figures do not establish a frost-hardiness limit.

People harvest wild trees for timber and use the roots in traditional medicine. The roots have a recorded use for female infertility. That record does not show that the treatment works. For propagation, sow seed soon after the fruit ripens. Remove all fruit pulp before sowing. A two-day soak helps loosen the pulp. Seed germination can be low and uneven, even with fresh seed. Many seeds sprout within two to three months. Others may take as long as two years.