Origin
Psydrax obovata (Klotzsch ex Eckl. & Zeyh.) Bridson subsp. obovata, commonly known as the bitter bush, is a plant species that belongs to the Rubiaceae family. It is endemic to South Africa and can be found in the provinces of Eastern Cape, KwaZulu-Natal, and Mpumalanga.
Common Names
Psydrax obovata is known by various common names in South Africa, including Bitterbos in Afrikaans, Umsenge in Zulu, and uNokwane in Xhosa.
Uses
The bitter bush has a variety of traditional medicinal uses in South Africa. The roots and leaves of the plant are used to treat fever, coughs, and colds. It is also used to treat stomach ailments, including diarrhea and dysentery. Furthermore, some traditional healers consider it a remedy for malaria. The plant is also used in cultural rituals such as purifications and initiations.
General Appearance
The bitter bush is a small, evergreen tree or shrub that can grow up to 5 meters tall. It has shiny, dark green leaves that are opposite and oval-shaped, measuring between 3 and 7 cm long. The plant produces small, white or cream-colored flowers that bloom from late winter to early summer. The fruits of the bitter bush are small and black when ripe, measuring between 4 and 8 mm in diameter. The bark of the tree is smooth and grey-brown.
Light Requirements
Psydrax obovata thrives in full sunlight to partial shade. It prefers bright light but cannot tolerate direct, intense sunlight for prolonged periods, which can damage the leaves and stunt the plant's growth. Hence, it is recommended to place the plant near a south-facing window where it can receive bright but diffused sunlight for 4-6 hours a day.
Temperature Requirements
The ideal temperature range for Psydrax obovata is between 60 and 85 degrees Fahrenheit. It can tolerate a wide range of temperatures but cannot withstand frost or extreme heat. Therefore, it is crucial to maintain temperature stability by keeping the plant away from drafty doorways, air conditioning, or heating vents.
Soil Requirements
Psydrax obovata prefers well-draining, slightly acidic soil with a pH range of 5.5 to 6.5. It is essential to use a high-quality potting mix that is rich in organic matter for the plant to thrive. Avoid using heavy clay soils that can retain excess moisture and suffocate the roots. It is recommended to add perlite or sand to the soil mix to increase drainage.
Cultivation Methods
Psydrax obovata is relatively easy to cultivate and can adapt to a range of growing conditions. It prefers a well-draining soil that is rich in organic matter. This plant can be grown in containers or in the ground and requires a bright, partially shaded location.
Watering Needs
Psydrax obovata likes moist soil, but it is important not to overwater it, as it can lead to root rot. Water the plant only when the top inch of the soil feels dry. Increase watering during hot, dry periods and reduce watering during cooler months.
Fertilization
Psydrax obovata benefits from regular fertilization to promote healthy growth and blooming. Use a balanced, slow-release fertilizer every six months during the growing season. Be sure to follow the manufacturer's instructions and apply the fertilizer sparingly to avoid burning the roots.
Pruning
Psydrax obovata responds well to pruning, which helps to keep the plant compact and encourages bushier growth. Prune in the late winter or early spring before new growth appears. Remove any dead or diseased branches and cut back about one-third of the plant's overall size. Pinch back the tips of new growth periodically throughout the growing season to promote bushiness.
Propagation of Psydrax obovata subsp. obovata
Psydrax obovata subsp. obovata can be propagated using both sexual and asexual methods. The plant is commonly propagated through seeds, stem cuttings, and air layering.
Propagation through Seeds
Seeds can be collected from the matured fruits of the plant. Prior to sowing, the flesh surrounding the seed must be removed. Germination of seeds can be improved by soaking them in water for 24 hours before planting. The seeds can be planted in well-draining soil mix in a pot or nursery bed, and kept moist until germination. Seedlings can be transplanted to a bigger pot or grown outside once they have developed enough roots and leaves.
Propagation through Stem Cuttings
Stem cuttings can be taken from a healthy adult plant during the growing season. It is recommended to use semi-hardwood stems as they have better rooting potential. Cuttings should be taken from the topmost portion of the plant and must have at least three nodes. Remove the lower leaves of the cutting, dip it in rooting hormone, and plant it in well-draining potting soil. Keep the soil moist and place the cutting in a warm, shaded area until it develops roots.
Propagation through Air Layering
Air layering can also be used to propagate Psydrax obovata subsp. obovata. This method involves wounding a branch by removing a section of bark, covering the wound with rooting hormone and moist moss, and wrapping with plastic or foil to create a moist environment. Roots will develop at the wounded portion over time. Once roots have developed, the branch can be cut below the rooting area and transplanted into a pot or nursery bed.
Disease Management
Psydrax obovata is highly susceptible to several diseases. Here are some common diseases and ways to manage them:
- Leaf spot: Leaf spot disease is characterized by the appearance of small, circular, brown spots on the leaves that gradually grow larger. The infected leaves might fall prematurely, leading to defoliation. To manage the disease, prune infected leaves and branches and destroy them. Use a fungicide as soon as the disease is noticed and follow the manufacturer's instructions.
- Anthracnose: Anthracnose is a fungal disease that causes leaves and branches to wilt and die. The affected leaves become brown, and the infected branches develop sunken lesions. Remove infected plant debris and tissue, apply a fungicide according to the instructions, and ensure proper air circulation around the plant to manage the disease.
- Root rot: Root rot is a disease caused by poor drainage and overwatering. The plant's roots turn brown and become soft and mushy. To manage root rot, ensure good drainage and avoid overwatering. Use a fungicide to prevent the spread of the disease and prune affected roots and stems.
Pest Management
Psydrax obovata is also susceptible to pest infestations. Here are some common pests that may affect the plant and ways to manage them:
- Aphids: Aphids are small, soft-bodied insects that suck the plant's sap and cause the leaves to curl and deform. Spray the plant with water to dislodge the aphids, or use a natural insecticide like neem oil to control their population.
- Spider mites: Spider mites are tiny arachnids that feed on the plant's leaves, causing yellowing and defoliation. They're often found on the undersides of the leaves. To manage spider mites, use a hose to spray the plant and increase humidity around it. You can also use natural remedies like neem oil or insecticidal soap.
- Thrips: Thrips are small, slender insects that feed on the plant's flowers and leaves. They cause distortion and discoloration of the plant's tissues. To manage thrips, use insecticidal soap or natural remedies like garlic oil spray or kaolin clay.
