Overview of Cussonia holstii Harms ex Engl.
Cussonia holstii Harms ex Engl., also known as the Kenyan bowline, is a tropical and evergreen tree that belongs to the Araliaceae family. This plant is native to the highlands of Kenya, in East Africa. It grows commonly in mixed tropical forest vegetation, grasslands, and along river banks at an altitude of 600-2,500 meters.
General appearance
The Kenyan bowline has a unique growth habit. It has a single, upright trunk, a well-formed crown, and its leaves are large and compound, with usually five to seven rounded leaflets. The leaves are arranged in a spiral pattern, giving the tree an overall impressive appearance. Cussonia holstii Harms ex Engl. can grow up to 25 meters tall, and its trunk can reach remarkable diameters of over a meter.
Uses
Cussonia holstii Harms ex Engl. has various medicinal, cultural, and economic uses. For centuries, locals have been using the tree to treat various ailments such as stomach ulcers, fever, and malaria. Additionally, the sap of the tree is believed to have some mild psychoactive effects and is sometimes used during traditional rituals. The wood of the tree is durable, hard, and termite resistant, making it a top choice in construction. Moreover, the bark of the tree is heavily used in traditional leather tanning, while the leaves and fruits are an important food source for forest elephants, monkeys, and birds.
Common names
Locally, Cussonia holstii Harms ex Engl. goes by various names, depending on the region. In Kenya, it is known as Mukinduri or Muthure among the Meru, Embu, and Mbeere communities. The tree is also sometimes referred to as the cabbage tree or the giant-cabbage tree in the western world, due to the resemblance of its leaves to that of a cabbage plant.
Light Conditions
Cussonia holstii Harms ex Engl. prefers to grow in full sun to partial shade. They are not tolerant of low light conditions and may wilt or become stunted if kept in a shaded area for prolonged periods. On the other hand, excessive exposure to direct sunlight may cause leaf scorching.
Temperature Requirements
The ideal temperature for the growth of Cussonia holstii Harms ex Engl. ranges between 18°C to 25°C. They are not frost tolerant and will die if exposed to a temperature below 0°C or frost. In regions with cool winters, it is ideal to grow Cussonia holstii Harms ex Engl. indoors or in a greenhouse.
Soil Conditions
Cussonia holstii Harms ex Engl. prefers well-drained soil that has a high content of organic matter. They grow best in slightly acidic to neutral soil with a pH range of 5.5 to 7.5. It is essential to avoid waterlogged soil or soil that is heavy on clay as this may cause root rot. Adding sand or perlite to the soil can improve drainage and aeration.
Cultivation Methods
Cussonia holstii Harms ex Engl., commonly referred to as the cabbage tree, is a slow-growing evergreen shrub that can grow up to 6 meters tall. This plant species is native to parts of East Africa, specifically Kenya and Tanzania. It is well suited for outdoor growing and can be grown in most temperate regions of the world. The Cussonia holstii Harms ex Engl. plant prefers well-draining soil and has a moderate tolerance to drought once established. It can be propagated from seeds or stem cuttings.
Watering Needs
Proper watering is essential to ensure the healthy growth of Cussonia holstii. The plant should be watered deeply at least once every two weeks during the growing season and once a month during the dormant period. However, this might vary depending on environmental factors, so it is important to monitor the soil moisture and adapt the watering frequency and quantity accordingly. The plant should not be overwatered as this can lead to root rot and other related issues.
Fertilization
Cussonia holstii requires fertilization during the growing season to maintain its health and vigor. A balanced fertilizer with a ratio of 10-10-10 or 20-20-20 is recommended for best results. The plant should be fertilized every two months during the growing season, from spring to fall. However, it is necessary to avoid applying excess fertilizer as it can cause leaf burn and damage to the plant's root system. Always follow the fertilizer label guidelines and use the appropriate amount for your plant.
Pruning
Pruning Cussonia holstii is essential to maintain its desired shape, remove any dead or damaged branches and promote healthy new growth. Pruning should be done during the dormant season, ideally in winter or early spring before the plant begins actively growing again. It is recommended to prune about one-third of the plant's overall size. Carefully remove any diseased or damaged branches using clean and sharp cutting tools. Dispose of the pruned branches immediately to avoid any possible spread of infection.
Propagation of Cussonia Holstii Harms ex Engl.
Cussonia holstii Harms ex Engl., commonly known as the Cabbage Tree or Mountain Cabbage Tree, is a tropical African plant that belongs to the Araliaceae family. It is a tree that can grow up to 13 meters tall and 2 meters wide. To propagate Cussonia holstii Harms ex Engl., different methods can be used:
Seed Propagation
This is the most common method used to propagate Cussonia holstii Harms ex Engl. The seeds are extracted from the mature fruits of the tree. After extracting the seeds, they should be cleaned and planted in a well-draining soil mixture. The soil should be kept moist, but not waterlogged. The seeds will germinate after about 3-4 weeks. Once the seedlings have sprouted, they can be repotted and grown in a nursery bed, ready to be transplanted after 6 months.
Cuttings Propagation
Another method of propagating Cussonia holstii Harms ex Engl. is through cuttings. The best time to take cuttings is during the early part of the rainy season. Select a stem that is about 30 cm long, and make a diagonal cut at the base of the stem. Remove all the leaves except the two or three at the top. Plant the cutting in a well-draining soil mixture, ensuring that the soil is moist at all times. The cutting will soon develop roots and can be transplanted after six months.
Air Layering Propagation
Air layering is another method of propagating Cussonia holstii Harms ex Engl. It involves wounding a stem of the tree and stimulating it to develop roots at the point of the wound. This method can be done any time of the year, but it is best done during the rainy season. Select a stem that is about 20 cm in length. Girdle the stem by removing a section of bark all around the stem using a sharp knife. Cover the wound with moist sphagnum moss and wrap it with polythene paper. After approximately six months, a new root system should have developed, and the newly rooted plant can be separated from the mother plant and transplanted to a new location.
Propagation of Cussonia holstii Harms ex Engl. can be done through seed propagation, cuttings propagation, or air layering propagation. Regardless of the method used, the process requires patience, care, and attention to detail.
Disease Management
One of the most common diseases that affect Cussonia holstii is fungal leaf spot disease. This disease is caused by fungi and can result in the development of brown spots on the leaves. In severe cases, the leaves may fall off the plant. To manage fungal leaf spot disease, it is important to remove any infected leaves and dispose of them properly. Additionally, ensure adequate spacing between Cussonia holstii plants to allow for sufficient air circulation and reduce humidity levels.
Another disease that can affect Cussonia holstii is root rot, which is caused by overwatering or poor drainage. This disease can lead to the deterioration of root systems and ultimately cause the death of the plant. To prevent root rot, ensure that the soil is well-drained and avoid overwatering Cussonia holstii.
Pest Management
Cussonia holstii is susceptible to attack by pests such as mealybugs, spider mites, and scale insects. Mealybugs and scale insects feed on the sap of the plant, while spider mites damage the leaves by puncturing the cells to feed on the chlorophyll content. These pests can cause stunted growth, yellowing of leaves, and ultimately lead to the death of the plant.
To manage the pests, it is important to regularly inspect Cussonia holstii plants for any signs of infestation. Mealybugs and scale insects can be removed by hand using a cotton swab dipped in rubbing alcohol. Spider mites can be managed by spraying the plant with a mixture of water and insecticidal soap. Avoid using harsh chemicals as they can damage the leaves of Cussonia holstii.
