Origin
Carissa longiflora (Stapf) Lawr. is a species of flowering plant in the Apocynaceae family. It is native to southern Africa, specifically in Zimbabwe.
Common Names
The plant has several common names, including Natal plum, Amatungulu (in Zulu), Amathungulu (in Xhosa), and Umthungulu (in Swazi).
Uses
The fruit of Carissa longiflora is edible and is used in traditional medicine for its medicinal properties. The fruit is high in vitamin C, calcium, and phosphorus. Additionally, the plant has ornamental value and is often cultivated as a hedge plant and for its attractive flowers.
General Appearance
Carissa longiflora is a shrub or small tree that can grow up to 2-4 meters in height. It has a dense canopy and spiny branches that provide protection against browsing animals. The leaves are glossy, dark green, and leathery with a prominent midrib. The flowers are small, white, and fragrant, and they bloom in clusters. The fruit is round, red to purple in color, and has a sweet and tangy taste. The plant prefers sandy soils and is drought-tolerant.
Growth Conditions of Carissa longiflora
Carissa longiflora (Stapf) Lawr. is a woody, evergreen shrub found in the African savannas. It grows commonly in Zimbabwe, Tanzania, Malawi, and Zambia. The plant can grow up to 5 meters and has a spread of about 3 meters.
Light requirements
Carissa longiflora requires full sun exposure to thrive. It can tolerate partial shade, but it does best in areas with maximum sunlight. Inadequate light may lead to poor growth and reduced flowering.
Soil requirements
The plant prefers well-drained, sandy, and loamy soils with a pH range of 6.0-8.0. Poorly drained and heavy soils are not suitable for the growth of Carissa longiflora. The plant can tolerate some level of drought once it is well established but requires regular watering during the growing season to aid optimal growth and fruit production.
Temperature requirements
Carissa longiflora can withstand a wide range of temperatures. It is well adapted to tropical and subtropical conditions and can tolerate high temperatures ranging from 13-40°C. The plant also requires a minimum temperature of 10°C during the winter season to prevent frost injury.
Nutrient requirements
The plant requires moderate nutrient levels to grow and produce an abundant fruit harvest. A balanced fertilizer with an N-P-K ratio of 4:1:2 or 2:1:1 is suitable for Carissa longiflora. Nitrogen and potassium are essential for the growth of the plant, while phosphorus aids in flower development and fruiting.
Cultivation Methods for Carissa longiflora (Stapf) Lawr.
Carissa longiflora (Stapf) Lawr., commonly known as Natal plum, is a hardy shrub that grows well in warm climates. It is native to South Africa but can be cultivated in other parts of the world. When planting Natal plum, choose a location that receives full sun and well-draining soil. Plant the shrub at the same depth as it was in the container or nursery bed.
Watering Needs for Carissa longiflora (Stapf) Lawr.
Natal plum requires moderate watering, especially during the growing season. Water the shrub once a week to keep the soil moist but not waterlogged. Reduce watering during the winter months to prevent root rot. Avoid overwatering, as the shrub cannot tolerate waterlogged soil.
Fertilization of Carissa longiflora (Stapf) Lawr.
Carissa longiflora (Stapf) Lawr. needs regular fertilization to grow healthy and produce abundant blooms. Apply a balanced fertilizer (NPK 10-10-10) every four to six weeks in the growing season. Avoid overfertilization, which can burn the roots and foliage. Stop fertilizing during the winter months.
Pruning Carissa longiflora (Stapf) Lawr.
Pruning is essential to keep Natal plum in shape and promote blooming. Prune the shrub in late winter or early spring before new growth emerges. Remove any dead, diseased, or damaged branches. Thin out the interior of the shrub to allow light and air to reach all parts. Cut back the tips of the branches to encourage lateral growth and more flowers.
Propagation of Carissa longiflora
Carissa longiflora (Stapf) Lawr., also known as Natal plum or Amatungulu in South Africa, is propagated mainly through seed and cuttings.
Propagation by Seed
Fresh seeds are collected from ripe fruits and cleaned off any fleshy material. The seeds are then soaked in water for 24 hours to soften their hard coat. They are then sown in containerized nurseries using a well-draining soil mix, taking care to plant them at a depth that is twice their size.
Seeds are best sown during the warmer months of the year, in the early spring or summer. The containers are placed in a warm and well-lit area and watered regularly to keep the soil moist. After germination, the seedlings are transferred to individual containers and grown for a further year before they are planted out in the field.
Propagation by Cuttings
The most common method of propagating Carissa longiflora is through stem cuttings. Semi-hardwood cuttings from the current season's growth, about 10-15 cm in length, are taken and the bottom cut is dipped in rooting hormone. A well-draining rooting medium, such as sand or perlite, is used in containers to root the cuttings.
The containers are placed in a warm and well-lit area and misted regularly to keep the cuttings moist. The cuttings are checked regularly for signs of rooting. Once rooting occurs, the cuttings are transplanted into individual containers and grown for a further year before being planted out in the field.
The best time to take cuttings is during the warmer months of the year, in the early spring or summer.
Disease Management
Carissa longiflora is relatively resistant to diseases, but several problems can occur, including:
- Phytophthora root rot - This soil-borne disease can affect a wide range of plants, including Carissa longiflora. Symptoms include yellowing leaves and wilting, and infected plants may eventually die. The best way to manage this disease is to avoid over-watering the plant and provide good drainage. Also, avoid planting in contaminated soil and use a fungicide if necessary.
- Leaf spot - A fungal disease that causes brown spots to appear on the leaves of the plant. If left untreated, the leaves may turn yellow and fall off. To manage this disease, remove any infected leaves and apply a fungicide to the remaining foliage.
- Powdery mildew - This fungal disease causes a white, powdery coating to appear on leaves and stems. It's generally more of a problem in humid conditions. The best way to manage powdery mildew is to improve air circulation around the plant, which can be achieved by pruning and thinning. Fungicides may also be used.
Pest Management
Carissa longiflora is also susceptible to several pests, including:
- Mealybugs - These small, white, cotton-like insects are common pest of Carissa longiflora. They suck sap from the plant and can cause stunted growth and weakened plants. To manage this pest, remove as many of them as possible by hand and use insecticidal soap or a systemic insecticide if necessary.
- Scale insects - Another sap-sucking insect that can infest Carissa longiflora. They appear as small, brown, oval-shaped bumps on stems and leaves. To manage scale insects, use a soft brush to remove as many as possible and use insecticidal soap or horticultural oil to control them.
- Spider mites - These tiny, spider-like pests can be a problem for Carissa longiflora, especially in hot, dry conditions. They suck sap from the plant, causing leaves to turn yellow and fall off. To manage spider mites, use a strong blast of water to knock them off the plant and use insecticidal soap or horticultural oil to control them if necessary.
