The natal plum is a beautiful tropical shrub. Like Indian hawthorn, it is used frequently in commercial landscapes. Its pretty white flowers are star-shaped and fragrant and produce edible red fruit. However, only the fruit is edible; the rest of the plant is toxic.
This shrub is classified as Carissa macrocarpa and is a member of the Apocynaceae (dogbane) family. You may also see it listed as Carissa grandiflora.
Other plants in the dogbane family include star jasmine (Trachelospermum jasminoides), mandevilla (Mandevilla spp.), oleander (Nerium oleander), periwinkles (Vinca major and Vinca minor), wax plants (Hoya spp.) and frangipani (Plumeria spp.).
This plant can be called natal plum, big num-num, Amatungulu or grootnoem-noem. Natal plum originally comes from Natal, South Africa, naturally inspiring the common name.
Preferred USDA Hardiness Zones
Choose this shrub if you are in zones 9 through 11. In zone 9, the shrub will do better if it is protected during winter. It may fall prey to winter chills and freezes but will regrow in the spring.
Size and Shape
This shrub is usually 2 to 8 feet tall but can be over 20 feet tall, depending on the variety you choose to plant.
Grow natal plum in a location that receives full sun for the best results. It will also do fine in part sun but will likely not have as many flowers and fruits.
Foliage, Flowers, and Fruit
Natal plum has ovate leaves that are dark green with a glossy sheen. They are usually 1 to 3 inches long and are formed along the branch in an opposite arrangement.
If you have smelled orange blossoms, you know what natal plum flowers smell like. The two plants have very similar scents. Each flower features five waxy petals arranged in a star shape.
You can eat the red fruit fresh or make it into jams, pies, tarts, syrups, pickles, sauces, or jellies. They will be bitter with lots of latex if eaten while unripe.
This shrub does have sharp spines, so it can work well as a barrier or hedge.
Be cautious when planting natal plum in a household with pets or children. The fruit is the only part of the plant that is not poisonous.
If you want a small variety that is 2 feet tall or under, look for 'Nana', 'Prostrata', 'Bonsai', 'Boxwood Beauty,' or 'Horizontalis'. 'Nana' and 'Boxwood Beauty' also have the advantage of no thorns.
If you live near the ocean, you can safely plant a natal plum, since they are quite tolerant of salty conditions.
For best results, plant natal plum in sandy soil that drains well, as this will help naturally deter root rot. If you have grown a specific variety and wish to have more plants, propagate new plants from cuttings to ensure all of the plants have the same characteristics. If you have a regular species of shrub, you can collect and plant the seeds from the mature plants.
Maintenance and Pruning
You can shape natal plum into a tree form or hedge through pruning. Trimming will also prompt the shrub to produce more flowers and fruit. You may need to prune plants that are close to a sidewalk so that pedestrians do not get stuck by the spines.
Use a fertilizer that has equal parts of nitrogen, phosphorus, and potassium. This will help maintain the shrub's general health and promote fruiting.
Pests and Diseases
You should not have many pest problems with this shrub. You may see Florida red scale (Chrysomphalus aonidum.) It does not do well with wet feet or overwatering and may fall prey to root rot in these situations.