Origin and Common Names
Acacia horrida (L.) Willd. subsp. benadirensis (Chiov.) Hillc. & Brenan, commonly known as Horrid Acacia or Horrid Thorn, is a shrub or small tree in the Fabaceae family. This plant is native to the arid regions of Africa, primarily found in Somalia, Djibouti, and Kenya.
General Appearance
Horrid Acacia is a thorny and spiny plant that can grow up to 5 meters tall. Its stems and branches are covered in sharp, hooked thorns that can pierce through clothing and skin. The leaves are bipinnate with small, oval-shaped leaflets that are grayish-green in color. The flowers are small and yellow, and the fruits are long, straight pods that are reddish-brown and contain several seeds.
Uses
Despite its name, Horrid Acacia has many beneficial uses. The plant is commonly used in traditional medicine to treat various ailments, including gastrointestinal issues, skin infections, and inflammation. The pods are edible and have been used as famine food in times of drought. Additionally, the wood is strong and durable, making it a valuable resource for building and furniture making in the local communities.
Light Requirements:
The Acacia horrida (L.) Willd. subsp. benadirensis (Chiov.) Hillc. & Brenan plant thrives well in full sunlight or partial shade. While it can tolerate some level of shade, it doesn't do well in complete shade as this can lead to stunted growth.
Temperature Requirements:
The Acacia horrida (L.) Willd. subsp. benadirensis (Chiov.) Hillc. & Brenan plant is found in areas with a subtropical climate that receives low to moderate rainfall. It can tolerate a wide range of temperatures ranging from 10°C to 35°C (50°F to 95°F). However, temperatures below 5°C (41°F) can stunt the growth of this plant.
Soil Requirements:
The Acacia horrida (L.) Willd. subsp. benadirensis (Chiov.) Hillc. & Brenan plant prefers well-drained soils with a pH ranging from slightly acidic to slightly alkaline. It can tolerate poor soils such as those with low nutrient content, high sand content, and those with low water holding capacity. However, it does not thrive well in waterlogged soils or those with poor drainage.
Cultivation
Acacia horrida (L.) Willd. subsp. benadirensis (Chiov.) Hillc. & Brenan is a relatively easy plant to cultivate and is suitable for growth in a range of climates. The plant can be propagated by seed or cuttings, although the latter method is more commonly used for cultivating new plants. Cuttings should be taken during the summer months and should be planted in a well-draining soil mix. It is also important to ensure that the soil is moist but not overly wet as this can lead to root rot or other fungal issues.
Watering Needs
The plant requires regular watering, particularly during periods of drought or hot weather. However, it is important not to overwater the plant, as this can lead to root rot or other issues. It is recommended to water the plant deeply but infrequently, allowing the soil to dry out slightly between waterings. When watering, be careful not to wet the foliage as this can lead to fungal issues.
Fertilization
Acacia horrida (L.) Willd. subsp. benadirensis (Chiov.) Hillc. & Brenan requires little in the way of fertilization. However, it can benefit from occasional applications of a balanced fertilizer during the growing season. It is important to avoid over-fertilizing, as this can lead to excessive growth and weaken the plant. It is recommended to fertilize the plant sparingly, following the manufacturer's instructions on the fertilizer package.
Pruning
Pruning is not strictly necessary for Acacia horrida (L.) Willd. subsp. benadirensis (Chiov.) Hillc. & Brenan, although some light pruning can help to maintain the shape of the plant and encourage bushier growth. Any dead, diseased, or damaged branches should be removed as soon as they are noticed to prevent disease from spreading and to maintain the plant's overall health. Pruning should be done during the dormant period in late winter or early spring.
Propagation of Acacia horrida subsp. benadirensis
Acacia horrida subsp. benadirensis can be propagated through various methods:
Seed Propagation
Seeds from mature fruits of the plant can be collected and sowed directly into the soil. The seeds should be planted at a depth of approximately 2 cm and covered with soil. Water should be applied regularly until the seedlings appear, and weeding should be done as needed. Seed propagation is best done during the planting season when the soil is warm and moist.
Cutting Propagation
Cuttings can be taken from semi-hardwood stems from the parent plant. The cuttings should be approximately 15 cm long and should be dipped in rooting hormone before being planted in a suitable rooting medium. The rooting medium should be kept moist, and the cuttings should be kept in a warm, shaded area until roots develop. Once roots are established, the cuttings can be transplanted into suitable pots or directly into the soil.
Air Layering
Air layering involves removing a portion of the bark on a stem and exposing the cambium layer. The exposed area is then covered with rooting hormone and wrapped with moist sphagnum moss and plastic wrap. Roots will develop at the exposed cambium layer, and the rooted section can be cut and planted into a suitable pot or directly into the soil.
Grafting
Grafting involves fusing a scion from the desired plant onto a rootstock from a different but closely related plant. This method is commonly used to propagate Acacia horrida subsp. benadirensis for commercial purposes. The rootstock used should be resistant to soil-borne diseases and should have a strong root system. The graft union should be kept dry and wrapped with grafting tape until the union is complete.
Disease Management
Acacia horrida subsp. benadirensis is susceptible to a few diseases, which can be effectively managed through good cultural practices. The following are some common diseases of the plant and suggested management strategies:
Canker
Canker is a common fungal disease that affects the stem of Acacia horrida subsp. benadirensis. It is characterized by the presence of sunken, reddish-brown lesions on the stem, which can cause wilting and death of the plant. The best way to manage canker is to remove the affected parts of the plant and destroy them. Avoid wounding the plant during pruning or other cultural operations, as this may create entry points for the fungus.
Root Rot
Root rot is another fungal disease that affects Acacia horrida subsp. benadirensis. It is caused by soil-borne fungi that attack the roots, resulting in discoloration, wilting, and stunted growth. To manage root rot, ensure good drainage, avoid overwatering and limit the use of fertilizers, especially nitrogen-based fertilizers. Implement crop rotation practices, and apply fungicides in the early stages of the disease.
Pest Management
Acacia horrida subsp. benadirensis is also susceptible to pests, which can cause severe damage to the plant. The following are some of the common pests that affect Acacia horrida subsp. benadirensis and suggested management strategies:
Scale insects
Scale insects are common pests that attack Acacia horrida subsp. benadirensis. They are small, immobile insects that attach themselves to the leaves, stems, and trunk of the plant, sucking the sap and weakening the plant. To manage scale insects, regularly inspect the plant for the presence of the pests. Physically remove the scales and apply insecticides if the infestation is severe.
Spider mites
Spider mites are tiny pests that feed on the plant sap, causing yellowing and wilting of the leaves. They also produce webbing, which can be unsightly. To manage spider mites, regularly water the plant and keep the humidity levels high. Introduce natural predators such as ladybugs or apply insecticides.
Caterpillars
Caterpillars are common pests that feed on the leaves of Acacia horrida subsp. benadirensis, causing defoliation and weakening the plant. To manage caterpillars, regularly inspect the plant for the presence of larvae, and physically remove them. Apply insecticides in the early stages of infestation if necessary.
