Overview:
Strophanthus gratus (Wall. & Hook.) Baill., commonly known as climbing oleander, is a tropical vine native to Africa and Madagascar. It belongs to the Apocynaceae family and is known for its medicinal properties.
Appearance:
The plant is a woody climber that can reach up to 20 m in length. It has dark green glossy leaves that are lanceolate in shape and arranged in pairs on the stem. The flowers are trumpet-shaped, fragrant, and white in color with reddish-brown stripes. The fruits are slender and contain seeds with a fuzzy, white coma.
Common Names:
In Africa, Strophanthus gratus is called "kajuk", "chombo", "mukombero", or "kaloli". In Madagascar, it is known as "vetambavy", "vona", or "hala".
Uses:
Strophanthus gratus is widely used in traditional medicine in Africa and Madagascar for its cardiac glycosides, which are compounds that affect the heart's rhythm. These compounds are used to treat heart failure, cardiac arrhythmias, and other cardiovascular conditions. The plant is also used as an aphrodisiac, a laxative, and a diuretic, among other uses. In addition, the seeds of Strophanthus gratus are used in the production of arrow poison.
Light Requirements
Strophanthus gratus (Wall. & Hook.) Baill. grows well in bright sunlight or partial shade. It requires a minimum of 4-6 hours of sunlight daily to thrive and produce flowers. Exposure to direct sun for prolonged periods may damage the foliage. Therefore, it is advisable to provide some shade during the hottest part of the day.
Temperature
The ideal temperature range for Strophanthus gratus (Wall. & Hook.) Baill. growth is between 18°C and 35°C. However, the plant can tolerate temperatures as low as 10°C and as high as 40°C. High humidity provides favorable conditions for growth, so it's advisable to maintain humidity levels of 60-70%.
Soil Requirements
Strophanthus gratus (Wall. & Hook.) Baill. grows best in well-drained soils with a slightly acidic to neutral pH range. A soil pH of 5.5 to 7.5 creates the best environment for root development and nutrient uptake. The soil should be rich in organic matter and have good water retention capacity. The ideal soil type is sandy loam with good drainage.
Cultivation Methods for Strophanthus gratus
Strophanthus gratus thrives in warm weather and humid conditions. It prefers a soil pH range of 5.5 to 6.8 and a well-draining soil. The plant requires a lot of sunlight and can be grown from seeds or cuttings.
Watering Needs for Strophanthus gratus
Strophanthus gratus requires consistent moisture in the soil, especially during the growing season. However, it is crucial not to overwater the plant, as this can lead to root rot. It is best to water the plant thoroughly and then wait for the soil to dry out slightly before watering again.
Fertilization for Strophanthus gratus
Strophanthus gratus requires regular fertilization to encourage growth and flowering. Use a balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium. Apply the fertilizer every two weeks during the growing season, and reduce to once a month during the dormant season.
Pruning Strophanthus gratus
Pruning is essential for Strophanthus gratus, as it helps to encourage new growth and maintain the plant's shape. Prune after flowering, removing any dead or damaged stems or leaves. Pinch back new growth to encourage branching and a compact growth habit. To prevent the plant from becoming too leggy, prune it regularly to keep its shape.
Propagation of Strophanthus gratus
Strophanthus gratus (Wall. & Hook.) Baill. can be propagated through various methods such as seeds, stem cuttings, and layering.
Propagation through Seeds
Propagation through seeds is the easiest and most common method for Strophanthus gratus. The seeds are collected from mature fruits and should be sown fresh, preferably during the rainy season. The seeds are sown at a depth of 1-2 cm in well-draining soil and kept moist until the seedlings emerge in about 3-4 weeks. The seedlings are then transplanted into individual containers.
Propagation through Stem Cuttings
Propagation through stem cuttings is another method for Strophanthus gratus. The cuttings should be taken from mature, healthy stems during the rainy season. The cuttings are best taken from the upper 1/3 of the stem and should be about 10-15 cm long. The cuttings are then dipped in rooting hormone and planted in well-draining soil. Keep the soil moist and provide partial shade until the cuttings have rooted, which could take 4-6 weeks. The rooted cuttings can then be transplanted into individual containers.
Propagation through Layering
Propagation through layering is a relatively simple method that can be done during the rainy season. Select a healthy branch from the middle or lower part of the plant and make a small wound on the bottom side of the branch. The branch is then bent and covered with soil. Ensure that the soil is moist and that the branch remains in contact with the soil. A new plant should form at the point of contact between the soil and the branch in about 3-4 months. The new plant can be separated from the parent and transplanted.
Disease and Pest Management for Strophanthus gratus
Strophanthus gratus (Wall. & Hook.) Baill. is a plant known for its medicinal properties. Like any other plant species, it is susceptible to various diseases and pests that can cause significant damage to the plant's health and overall growth. Here are some common diseases and pests that affect Strophanthus gratus and ways to manage them:
Common Diseases
Leaf Spot: Leaf spot is caused by fungi and appears as dark spots on the leaves. The affected leaves eventually turn yellow and fall off. To manage leaf spot, remove the infected leaves and destroy them. Fungicides can also be applied to prevent the spread of the disease.
Root Rot: Root rot is caused by fungi and typically develops in plants with poor drainage. Symptoms of root rot include yellowing leaves and a general drooping of the plant. To manage root rot, improve drainage around the plant and avoid overwatering. Fungicides can also be used to control the disease.
Common Pests
Aphids: Aphids are small insects that suck sap from the plant, causing stunting and distortion of leaves and flowers. To manage aphids, remove them from the plant with a strong spray of water or use insecticidal soap or oil.
Spider Mites: Spider mites are tiny pests that feed on the undersides of leaves, causing yellowing and stippling. To manage spider mites, spray the plant with a strong jet of water or use insecticidal soap or oil.
Scale Insects: Scale insects are small, oval-shaped insects that attach themselves to the plant's leaves and stems, sucking sap and causing yellowing and leaf drop. To control scale, remove them from the plant with a cotton swab dipped in rubbing alcohol or use insecticidal soap or oil.
Overall, managing diseases and pests in Strophanthus gratus involves practicing good horticultural practices such as proper watering and fertilization, monitoring for signs of disease and pests, and taking appropriate measures to manage them.
