Although the splendid Olea capensis subs. macrocarpa may grow slowly, if planted in the right place, the shade of these breathtakingly handsome trees will be enjoyed for many generations to come as these trees can reach a great age. Second only in size, to the massive yellowwoods of the forests along the Southern Cape coastline, but not having suffered the extensive exploitation of the yellowwoods, these awe inspiring trees can reach an age of between 2000 and 3000 years. In the forest they can grow as tall as 35 – 40m but will rarely achieve that height in cultivation where a maximum of about 10m can be expected. The attractive panicles of sweetly scented flowers attract a variety of insects while the fruit is relished by birds as well as other wildlife.
Olea capensis subs. macrocarpa
RSA National Tree No’
The Black ironwood is a most rewarding and beautiful shade tree but one should carefully consider the positioning of these trees before planting as they are slow to reach maturity and become a permanent fixture in the landscape. These must surely be amongst the finest of ornamental trees to plant as a legacy for future generations so it is important to ensure that wherever these trees are planted, there is enough space to enable them to grow unhindered, so that their full glory can be appreciated for many years to come. As specimen trees, Olea capensis subs. macrocarpa are unsurpassed or if you wish to create a truly imposing avenue, these trees will provide a permanent, evergreen thoroughfare for all to admire. The bonsai enthusiast will find the Black ironwood well worth the effort and challenge.
|Height||6 - 10m|
|4 - 8 m|
The Black ironwood occurs in a wide variety of habitats but is most commonly found in moist to semi-moist high forest although in some regions they do grow in drier areas and bushveld.
On younger trees the bark is pale grey but becomes darker and vertically fissured as the tree ages. If the bark is damaged the wound exudes a distinctive dark gum.
The glossy, medium to dark green, opposite leaves are paler green underneath and are narrowly elliptic, tapering at the base of the apex. The petiole is sometimes purple.
The small, white or cream sweetly scented flowers are borne in abundant terminal heads from November to January. The flowers are bisexual.
The fruit which is a fairly large, fleshy, oval drupe ripens to purplish black and looks similar to large Greek olives.
The seed consists of a brownish, oval pip inside the fruit.
The Black ironwood is widespread and grows in coastal forests from the Western Cape through to the Eastern Cape, up into Kwa-Zulu Natal and further north to Limpopo.
Olea capensis subs. macrocarpa will grow successfully in shade or sun. As these trees grow rather slowly it helps to provide absolutely optimal conditions for the first few years by preparing a large hole before planting and enriching the soil with plenty of compost and high nitrogen organic fertilizer. Apply a thick layer of mulch around the tree and keep well watered.
|Spring - Summer|
Black ironwood is hardy once established and will withstand some frost as well as dry conditions.
Propagation from seed is quite a lengthy process as the seeds can take up to six months to germinate and the saplings grow quite slowly. Soft wood cuttings taken in spring usually provide a more successful and quicker method of propagation.
The name ironwood speaks for itself as the timber from these magnificent trees is extremely hard and heavy. The timber is grey-brown to brown with a fine straight grain and attractive yellow, black and grey figuring. This durable wood is oily and difficult to work but is excellent for turning and gives a beautiful, smooth finish. Previously, the wood was used for railway sleepers, wagon building, bridge construction and mine supports but increasingly this fine timber is gaining popularity for the manufacture of fine furniture, veneers and flooring.