Plant Description:
Dichrostachys cinerea (L.) Wight & Arn. var. tanganyikensis Brenan & Brummitt is a woody plant that belongs to the family Fabaceae, commonly known as the Pink Senna or Chinese Lantern Tree. It is a small, spiny tree that can grow up to 15 meters tall with a trunk diameter of 30 centimeters. The bark is grayish-brown in colour with rough texture and bears horizontal stripes. The leaves are bipinnate with small leaflets that are dark green in colour and arranged alternately on the stem.
Plant Origin and Distribution:
The Pink Senna is native to the African continent and is found in numerous countries within the region, including Botswana, Namibia, Zimbabwe, Kenya, Tanzania, and South Africa. It is also found in some parts of Madagascar. The plant is now widely distributed and naturalized in various countries beyond Africa.
Common Names:
The plant has several common names depending on the region. It is commonly known as Pink Senna or Chinese Lantern Tree, with other names including Sickle Bush, Kalahari Christmas Tree, and Bell Mimosa.
Plant Uses:
The Pink Senna serves several purposes. In traditional African medicine, the bark and roots of the plant are used to treat various ailments, including diarrhea, dysentery, and fever. The plant is also utilized in many regions as a source of firewood, charcoal, and timber. The fruit pods are used as a source of animal feed and may possess medicinal value that is currently being studied. The plant is also cultivated as an ornamental tree because of its bright pink flowers and feathery foliage.
Growth Conditions for Dichrostachys cinerea var. tanganyikensis
Light: Dichrostachys cinerea var. tanganyikensis prefers full sunlight exposure. The plant can tolerate partial shade, but full sunlight exposure is ideal for growth and flowering.
Temperature: The plant prefers warm to hot climate conditions, and it can tolerate a range of temperatures from 20°C to 35°C. Dichrostachys cinerea var. tanganyikensis can grow in semiarid regions, and it can withstand dry and hot temperatures during the day and cooler temperatures at night.
Soil: Dichrostachys cinerea var. tanganyikensis can grow in a range of soil types, but it prefers well-drained soils that are nutrient-rich. The plant can grow in sandy or loamy soils, but it cannot tolerate waterlogged conditions. The soil should have a pH range of 6.0 to 7.5 for optimal growth.
Water: The plant can tolerate occasional drought conditions, but it requires regular watering to sustain growth and flowering. During the growing season, the plant should be watered once every two weeks. In the dry season, watering should be increased to once every week. The plant should be watered deeply to encourage deeper root growth.
Cultivation Methods
Dichrostachys cinerea (L.) Wight & Arn. var. tanganyikensis Brenan & Brummitt can be propagated by seeds, stem cuttings, and layering. It prefers a warm, dry climate with well-drained soil. The plant requires full sunlight exposure and should be planted in an area protected from strong winds.
It is ideal for growing in pots or containers, and you can move the plant indoors during winter to prevent frost damage. The plant has low water needs, making it easy to maintain.
Watering Needs
The plant prefers dry to medium soil moisture levels and should be watered only when the soil is completely dry. Too much water on the plant can lead to root rot, a common problem with the plant. A good practice is to soak the soil until it is completely saturated, then allow the water to drain out of the pot or container before the next watering session.
During winter, the watering frequency should be reduced to allow the plant to go into dormancy. Too much water during this period can cause the roots to rot.
Fertilization
Dichrostachys cinerea (L.) Wight & Arn. var. tanganyikensis Brenan & Brummitt has low fertilizer needs and can grow well without fertilizers. However, adding a balanced fertilizer once or twice a year can help improve the plant's growth.
A slow-release fertilizer applied during spring or early summer is ideal. The amount of fertilizer to apply depends on the size of the pot or container and the plant's growth stage.
Pruning
The plant requires minimal pruning. Removing dead or weak branches helps maintain the plant's shape and stimulates new growth. You can prune the plant in early spring before new growth appears.
If the plant becomes too leggy or loses its shape, cut back the stems to 3-4 inches from the base. The plant will regrow from the pruned areas. Regular pruning helps maintain the size and shape of the plant.
Propagation of Dichrostachys cinerea var. tanganyikensis
Dichrostachys cinerea var. tanganyikensis can be propagated through various methods such as seed propagation, vegetative propagation, and cuttings.
Seed propagation
Seeds are the easiest and most common propagation method for Dichrostachys cinerea var. tanganyikensis. The seeds can be collected from the plant when ripe and sown in a seedbed or directly in the field. The seeds should be planted at a depth of approximately 2 cm, and the bed must be kept moist until germination. Germination can take anywhere from 10 days to a month.
Vegetative propagation
Dichrostachys cinerea var. tanganyikensis can also be propagated vegetatively through root suckers. Root suckers are young plants that grow from the roots of an existing plant. They can be separated from the parent plant and transplanted to another location. The parent plant should have a well-established root system before propagating through root suckers.
Cuttings
Cuttings are another method of propagation for Dichrostachys cinerea var. tanganyikensis. Semi-hardwood cuttings are taken in the spring or early summer from the current year's growth. The cuttings should be approximately 15 cm long with two or three nodes. The leaves on the lower part of the cutting should be removed, and the stem should be planted in a rooting hormone and then in a well-draining soil mix. The cuttings should be kept in a humid environment and protected from direct sunlight until they establish roots.
Disease Management for Dichrostachys cinerea var. tanganyikensis
Dichrostachys cinerea var. tanganyikensis is relatively resistant to diseases, but some common fungal and bacterial diseases can affect the plant:
- Leaf spot: This is a fungal disease that causes small, dark spots on the leaves. To manage this disease, avoid overhead watering and remove infected leaves.
- Canker: This is a fungal disease that causes sunken lesions or cankers on the branches or trunk of the plant. To manage this disease, remove infected branches or the entire plant if necessary.
- Bacterial leaf blight: This is a bacterial disease that causes water-soaked spots on the leaves that later turn brown. To manage this disease, remove infected leaves and avoid overhead watering.
Pest Management for Dichrostachys cinerea var. tanganyikensis
Dichrostachys cinerea var. tanganyikensis is also relatively resistant to pests, but some common pests that can affect the plant are:
- Mites: These are small pests that feed on plant sap and can cause stunted growth and distorted leaves. To manage mites, use a miticide and keep the plant well-watered and fertilized.
- Scale insects: These pests secrete a sticky substance that attracts ants and can cause yellowing of leaves. To manage scale insects, use an insecticide and prune infected branches.
- Caterpillars: These pests can eat the leaves and cause defoliation of the plant. To manage caterpillars, use a natural predator such as birds or use an insecticide.
