By Julia Eder
Carissa is a shrub, climber, or small tree that can grow up to 20 feet tall and it is cultivated for its plum-like fruits. The berries are used mainly for processed products such as jellies, preserves, or syrup, but they are also eaten fresh. They contain a little more vitamin C than oranges, and are also a source for other vitamins, including Vitamin A and B.
The species that is mainly produced is Carissa Macrocarpa, or Natal plum, named after a region in Northern South Africa where it grows. There, it is locally called num-num. The Natal plum is a significant commercial resource in South Africa where farmers sell them along the roadsides every January and February.
Carissa can be difficult to grow because the plant exudes a milky sap when cut or broken, which aggravates harvest and transportation of the fruits because they can easily be damaged. And the berries have a short shelf life because the sap congeals.
Carissa is also a popular and cultivated hedge plant because of its thick, dark glossy green leaves, its thorns, and the fragrant white to pink star-like blossoms. It has even become a valued ornamental plant in California and Florida. There, some plants have been selected and reared to have fruits as big as oranges and are grown on a height above the thorny foliage to facilitate the harvest. With further horticultural advancement, carissa can be useful in at least a dozen nations within Africa and in other parts of the world for economic profit.
Carissa can be grown in multiple regions—there are about 30 species of carissa in the tropics and subtropics of Africa, Asia and Australia. Although most species of carissa occur in well-watered zones, some of them like Carissa haematocarpa, hold promise as a dry land crop. Carissa is also tolerant to extreme sunlight, shade, and salty soil. It is easy to grow and the productivity is high at about three tons per hectare, which is considered a minimal yield under commercial production in South Africa.
Not only is the crop a valuable source for nutrition, it can became a huge source of income for African farmers and has the potential to do well in a global market. As carissa tastes a little bit like cranberry, it could also be as commercially successful as the billion-dollar fruit, according to the National Research Council.
Do you think carissa could become as popular as a cranberry? Let us know in the comments!
Julia Eder is a media and communications intern with the Nourishing the Planet project.