The Carissa genus belongs to Apocynaceae (Dogbane) family. The botanical name for that family is Apocynaceae which is Greek for “keep it away from the dog” meaning it kills them easily. Apocynaceae, family of flowering plants, include about 400 genera and 4555 species of trees, shrubs, woody vines, and herbs. Members of the family are distributed primarily in tropical and subtropical areas of the world. Nearly all members of this family are poisonous, and some species are used medicinally.

A number of the Apocynaceae family members are cultivated as ornamentals; best known are Adenium obesa (Desert Rose), Mandevilla splendens (Rock Trumpet), Allamanda cathartica (Golden Trumpet), Plumeria alba (Frangipani), Nerium oleander (Oleander), Vinca major (Big Periwinkle), Asclepias curassavica (Blood Flower), Hoya carnosa (Wax Flower), Thevetia peruviana (Yellow Oleander), Trachelospermum jasminoides (Star Jasmine), Amsonia elliptica (Bluestar) Carissa bispinosa (Natal plum).

Carissa macrocarpa is a broadleaf, evergreen fast-growing, dense ornamental shrub. Carissa, comes from the Sanskrit word “corissa” the local name of one species. Macrocarpa is Greek for “large fruit”. It grows in coastal bush, coastal forests and on sand dunes, from South Africa to Mozambique.

All parts of the Natal Plum are poisonous, except for the red-ripe fruit. It usually forms a dense thorny shrub 1-2 metres high but it can grow into a small tree up to 4 metres high. Shiny, dark green leaves are simple, opposite, ovate to round, 3-6 cm long. The tips of the leaves are sharply or bluntly pointed. Branches have Y shaped thorns, but usually thorns are smaller and less than the Carissa spinosa. The young branches are green and all parts of the plant exude white, milky latex. The plant blooms most profusely from spring to midsummer, but produces a few flowers throughout the year. Solitary, 5-petaled, star shaped flowers are 3-5 cm in diameter, white and scented like orange blossom. Fleshy fruits are oval, somewhat the size of plums, 2-4 cm long. The colour of the fruit at first is green, when it is ripe turned red or purple. The fruit matures in approximately 60 days, yielding most of its fruit in the summer. The fruit is edible and is rich in vitamin C, magnesium and phosphorus.

As Carissa macrocarpa originate from coastal areas, it is able to tolerate salt-spray, and the strong winds accompanying it, as well as saline soils. It is easy to grow plant, does not mind full sun or light shade.  It is also not particular about soil, can be grown at all types of the soil. Plant is sensitive to frost damage, can withstand -4°C for a short time.

Natal Plum is a perfect hedge plant, it is preferred particularly in coastal areas since highly salt-tolerant. To make a dense, impenetrable hedge; they should be planted one metre apart. A low growing form of Carissa macrocarpa, “Green Carpet” is a popular groundcover plant which seldom grows more than 40 cm height. Plant can be pruned if necessary. Carissa’s, normally grown from seed, but can also grow from cuttings.

In its homeland, the Carissa is pollinated by night-flying insects. Other countries some plants do not produce fruit at all. It has been found that unproductive plants, apparently self-infertile, will bear fruits after cross-pollination by hand.

USE IN LANDSCAPE: Natal Plums (Carissa macrocarpa and Carissa bispinosa) are of decorative value as an ornamental; because of the contrast in shining green leaves, white flowers and bright red fruit. Both are suitable for container planting, will survive in shady areas, respond well to pruning, and make a lovely bonsai subject.

They can be used for mass planting, ground cover, espalier and to make a hedge. They make lovely, decorative hedges, both formal and informal.

The fruits may be eaten fresh but it is more enjoyable when cooked.  Delicious jams or jellies made from the fruit. Some varieties have been selected for good fruit bearing quality.