Harpephyllum caffrum

Harpephyllum caffrum, sometimes nicknamed the African plum, is a tree with evergreen foliage that is rare in cultivation, mainly due to its sensitivity to cold. Native to South Africa, it is valued there for its natural robustness. It is cultivated for the beauty of its foliage, its nectar-rich summer flowering, and its small, tangy red fruits. It can be grown in the ground in regions with very mild climates, while elsewhere, it adapts well to pot cultivation, to be overwintered frost-free. Its elegant appearance will be showcased in a very sheltered Mediterranean garden, a bright greenhouse, or a large conservatory.

Harpephyllum caffrum belongs to the Anacardiaceae family, just like the mango tree, pistachio trees, and Cotinus. Native to southern Africa, its range extends from the Eastern Cape province in South Africa, through KwaZulu-Natal, Eswatini (Swaziland), southern Mozambique, up to Zimbabwe. In its natural habitat, it is mainly found in riverine forests, often along watercourses, at altitudes up to 1,400 m. Its hardiness is debated, but it is generally accepted that this tree can only tolerate very light frosts (-1 to 3 °C). This African plum can reach a height of 10 to 20 m in the wild, with a straight and slender trunk. Its crown is dense and fairly broad. The bark is smooth in young specimens, becoming rough and greyish-brown with age. The curved and ascending branches form a dense, rounded crown. The compound and pinnate leaves measure between 15 and 25 cm in length and consist of sickle-shape, dark green and glossy leaflets, sometimes speckled with reddish hues. The flowering, which occurs in summer in the northern hemisphere, takes the form of small yellowish to greenish flowers, clustered in terminal panicles. It is a dioecious species: male and female flowers are found on separate trees. Female trees produce ovate, fleshy fruits, initially green, then red when ripe, measuring about 2 cm in diameter. These drupes, containing a single seed, are enjoyed by various species of birds and mammals. They are also consumed as jellies, jams, or fermented beverages in South Africa.
The root system of Harpephyllum caffrum is robust and can be aggressive. It is therefore recommended to plant this tree at a minimum distance of 4 to 6 m from built structures to avoid potential damage.

In South Africa, Harpephyllum caffrum makes an excellent shade tree, often used in gardens and urban landscaping. Its growth is relatively fast, especially under optimal conditions. Although drought-resistant, it is sensitive to frost, which limits its cultivation in temperate climates.