Origin
Oxygonum buchananii (Dammer) J.B.Gillett is a plant species that belongs to the family Polygonaceae. It is native to East Africa, specifically Kenya, Tanzania, and Ethiopia.
Common Names
This plant is commonly known by several names, such as East African Sorrel, Buchanan's oxygonum, and in Swahili, it is referred to as "Mnafu".
General Appearance
Oxygonum buchananii is a trailing herbaceous perennial plant that can grow up to 1 meter in length, with a nodose stem that can root at the nodes. Its leaves are succulent, with long petioles and triangular or ovate blade shape, with red-tinged margins. The plant bears small, white or pink flowers at the branch tips. Its fruits are achenes which are red or black, and ovoid or nearly globose in shape.
Uses
The plant is popularly used in East African cuisine as a souring agent to flavor stews, curries, and soups. The leaves of the plant are edible and have a lemony taste. Additionally, it has medicinal benefits and is used to treat gastrointestinal infections and fever.
Growth Conditions for Oxygonum buchananii
Oxygonum buchananii is a perennial herbaceous plant that typically grows in rocky places, among stones or on open gravelly or sandy soils. It is native to Africa, specifically found in Somalia, Kenya, Tanzania, Zambia, Mozambique, and South Africa.
Light
The plant thrives well under full sun exposure. It requires a lot of light for photosynthesis, and the leaves turn yellow if the plant receives less light. Therefore, it is essential to grow it in locations where it receives at least six hours of full sunlight.
Temperature
Oxygonum buchananii prefers warm to hot climates with temperatures ranging between 25°C and 35°C. The plant can tolerate high temperatures and drought, making it suitable for dry and arid regions. However, temperatures below 18°C may lead to slow growth or the plant's death.
Soil
The plant does well in a well-drained and gritty soil type that is not too fertile. It requires soil with a pH of 6.5 to 7.5, and it can tolerate different soil types, including loam, sand, and clay. However, the soil must not be waterlogged as the plant may rot.
In conclusion, Oxygonum buchananii prefers full sun exposure, warm to hot temperatures, and well-drained soils that are gritty and not too fertile. Understanding these growth conditions is essential in providing suitable conditions for the plant's growth and development.
Cultivation methods
Oxygonum buchananii (Dammer) J.B.Gillett is a low-growing plant preferring sandy soils with excellent drainage. It is advisable to cultivate this plant in a partially shady area, especially during summer months. Planting can be done at any time of the year, but the ideal period is during the rainy season.
Watering needs
Watering is crucial for the optimal growth and development of Oxygonum buchananii. Ensure to keep the soil moist but not waterlogged, especially during the first three months. After that duration, the plant can tolerate minor changes in the soil moisture levels. During the dry seasons, it is advisable to water the plant at least once a week to maintain the soil moisture.
Fertilization
Applying fertilizers can significantly enhance Oxygonum buchananii's growth and development. It is best to apply organic manure such as animal waste or compost at least twice a year. The application of nitrogen fertilizer should be avoided since the plant is remarkably sensitive to nitrogen. Ensure to apply the correct amount of fertilizer that matches the plant's requirements and follow the manufacturer's instructions.
Pruning
Pruning Oxygonum buchananii is not a critical requirement, but it makes the plant looks tidy and well-manicured. The best time to prune the plant is during the dry seasons, mainly between June and August. Prune the plant by trimming any excess or overgrowing shoots. Additionally, remove any dead or diseased leaves and stems since this can help to prevent the spread of any disease.
Propagation of Oxygonum buchananii
Oxygonum buchananii (Dammer) J.B.Gillett is commonly propagated through both vegetative and generative means. The following are the propagation methods that can be employed for the plant:
Seed Propagation
The seeds of Oxygonum buchananii can be propagated through seed propagation. The seeds are collected as soon as they ripen and they are then sown in sterilized soil. Before sowing, the seeds can be soaked in water for up to two days to enhance germination. A mixture of sand and manure can also be added to the soil to ensure optimal growth.
The pots are then placed in a shaded area until the seedlings are established. Regular watering is essential during this stage to ensure optimal growth. Once the seedlings have grown to a certain height, they can be transplanted into larger pots or to the ground.
Vegetative Propagation
Oxygonum buchananii can be propagated using vegetative means. This method involves the use of cuttings from the stem of the plant, which is then planted in a suitable soil mixture. The cuttings are taken from healthy stems and they should measure at least 10cm in length. The cuttings are then planted in a well-draining soil medium and placed in a humid area that is protected from direct sunlight.
To ensure successful propagation, the cuttings should be regularly misted, and the soil should be kept moist. After about three weeks, the cuttings should have established roots and can be transplanted into pots filled with growing soil and placed in a shaded area.
Oxygonum buchananii can also be propagated through root and stem division. This method involves separating healthy roots or stem segments from the parent plant and planting them in a suitable soil mixture. Care should be taken when handling the divided plant parts to avoid damage to the roots.
Disease Management for Oxygonum buchananii
As with any plant, Oxygonum buchananii is susceptible to a range of diseases. The most common diseases that affect this plant include root rots, leaf spots, and powdery mildew.
To manage root rots, ensure proper drainage and avoid overwatering. Infected roots should be cut and removed, and the plant should be treated with a fungicide.
Leaf spots can be managed by removing and destroying infected leaves. In severe cases, a fungicide may be necessary.
Powdery mildew can be prevented by avoiding overhead watering and providing good air circulation around the plant. If an infection occurs, a fungicide may be necessary.
Proper sanitation practices, such as cleaning pruning tools, can also help prevent the spread of diseases.
Pest Management for Oxygonum buchananii
Some common pests that may affect Oxygonum buchananii include spider mites, aphids, and mealybugs.
Spider mites can be managed by regularly misting the plant to increase humidity and using a miticide if necessary.
Aphids can be removed with a strong spray of water or by introducing natural predators, such as ladybugs or lacewings.
Mealybugs can be controlled by manually removing them with a cotton swab dipped in rubbing alcohol, or by using a systemic insecticide.
Regular monitoring and prompt action can help prevent pest infestations from becoming severe.
In conclusion, establishing a good management plan can ultimately prevent diseases and pests from damaging the Oxygonum buchananii plant. By implementing the above-mentioned practices, gardeners can maintain a healthy and thriving plant.
