Overview
Psydrax horizontalis (Schumach.) Bridson is a species of flowering plant in the Rubiaceae family. It is known by several common names, including the coffee bush, horizontal psydrax, and dwarf psydrax.
Origin and Distribution
The plant is native to tropical regions of Africa, specifically in Cameroon, Congo, Gabon, Nigeria, and Sierra Leone. It grows in rainforests, along riverbanks, and in coastal forest areas.
General Appearance
The coffee bush is a small to medium-sized evergreen shrub that can reach up to 5 meters in height. Its leaves are shiny and dark green with a rounded shape and pointed tip. The plant produces small, white, fragrant flowers that bloom in clusters in the summer. The fruit is a small, fleshy drupe that turns from green to red when mature.
Uses
The coffee bush has various uses in traditional medicine. Its leaves and bark are used to treat fevers, headaches, and stomach ailments. The plant's fruit has been historically used as a substitute for coffee beans. It is also commonly used as an ornamental plant in gardens and landscaping.
Light Requirements:
Psydrax horizontalis (Schumach.) Bridson prefers bright, indirect light. Direct sunlight can scorch the leaves of the plant. In areas with low light, the plant can survive, but growth may be stunted.
Temperature Requirements:
The plant grows best in temperatures between 65-80°F (18-27°C). The minimum temperature for growth is 55°F (13°C), and it cannot tolerate temperatures below 50°F (10°C).
Soil Requirements:
The plant requires well-draining soil with a slightly acidic to neutral pH (around 6.0-7.0). A good soil mix consists of one part potting soil, one part peat moss, and one part perlite or sand to improve drainage.
The plant is sensitive to high levels of salt, so avoid using heavily fertilized or saline soils.
Water Requirements:
Psydrax horizontalis (Schumach.) Bridson prefers moist soil but is susceptible to root rot in waterlogged soil. Water the plant when the top inch of soil is dry. Reduce watering during the winter months when the plant is dormant.
Fertilizer:
The plant requires regular fertilization during the growing season (spring and summer). Use a balanced, water-soluble fertilizer at half the recommended strength every two to three weeks. No fertilizer is needed during the winter dormancy period.
Cultivation of Psydrax horizontalis
Psydrax horizontalis can be propagated from seeds or cuttings. The best time to plant this shrub is in spring or early summer when the temperature is warm enough for it to grow.
The plant grows best in a well-draining soil that is rich in organic matter. It prefers a slightly acidic to neutral pH range of 5.5 to 7.0.
Watering needs of Psydrax horizontalis
Psydrax horizontalis should be watered regularly to keep the soil moist, especially during the first year of growth. Once established, the plant is drought-tolerant and can survive without watering for a few weeks. However, it's always best to water your plant when the soil is dry to the touch.
Watering should be reduced during the winter months to prevent root rot, which can occur when the soil is too wet.
Fertilization of Psydrax horizontalis
Psydrax horizontalis is a moderately fast-growing plant that requires regular fertilization to maintain its health and vigor. Use a balanced fertilizer that is rich in nitrogen, phosphorus, and potassium. Fertilize the plant at the beginning of the growing season and again in late summer.
Avoid over-fertilization, as it can lead to excessive foliage growth at the expense of flowers. Follow the manufacturer's recommendations on how much fertilizer to use based on the size of your plant.
Pruning Psydrax horizontalis
Psydrax horizontalis requires minimal pruning, but occasional maintenance is necessary to keep it looking neat and compact. Prune the plant after it has finished flowering to remove any dead or damaged wood and to shape the plant to your desired size.
Remove any suckers that grow from the base of the plant to encourage upward growth.
Avoid pruning during the winter months when the plant is dormant, as it can stress the plant and stunt its growth.
Propagation of Psydrax horizontalis
Psydrax horizontalis is commonly propagated through seeds, cuttings, and layering.
Seed Propagation
Seeds of Psydrax horizontalis are collected from mature fruits and sown in seedbeds with well-draining soil. The seeds are then covered with a thin layer of soil and kept moist. Germination usually occurs within 2-3 weeks. The seedlings are then transplanted into individual pots once they grow their second pair of leaves.
Cutting Propagation
Cuttings of Psydrax horizontalis are taken during the spring or summer months. The cuttings should be 6-8 inches long and have at least 3-4 leaves. The base of the cutting is then dipped in rooting hormone and inserted in a pot filled with a well-draining potting mix. The pot is then covered with a clear plastic bag to maintain high humidity levels. The cuttings should root within 4-6 weeks, and the plastic bag can be removed once new growth appears.
Layering Propagation
Layering is a common propagation method for plants with low-lying branches, such as Psydrax horizontalis. This method involves bending a lower branch towards the ground and wounding the underside of the branch. The wounded part of the branch is then covered with soil and kept moist. Roots should start growing from the wounded area within 2-3 months. Once the roots are established, the new plant can be separated from the parent plant and transplanted into a new location.
Disease Management
Psydrax horizontalis (Schumach.) Bridson is generally a hardy and disease-resistant plant. However, it can be susceptible to some plant diseases, which can cause damage and reduce plant vigor.
Bacterial leaf spot is one of the common diseases that affect Psydrax horizontalis. This disease manifests as small water-soaked spots on the leaves, which eventually turn brown and fall off, leaving the plant looking unsightly. To manage this disease, it is advisable to remove the affected leaves and branches and dispose of them safely. Infected plants should also be isolated to reduce the spread of the disease. In severe cases, copper fungicides can also be used to control the bacteria.
Fungal diseases such as powdery mildew can also affect Psydrax horizontalis. This disease is characterized by a fuzzy white growth on the leaves, which can hinder photosynthesis and cause plant deformities. The best way to manage powdery mildew is to remove the infected leaves and improve air circulation around the plant. Fungicides such as neem oil and sulfur can also be used to control the fungal growth.
Pest Management
Psydrax horizontalis can also be attacked by some pests, which can cause physical damage and weaken the plant's interaction with the environment. Here are some of the common pests and ways to manage them:
Aphids are sucking insects that feed on the plant's sap and excrete sticky honeydew, which can attract other pests and promote fungal growth. To manage aphids, it is advisable to use a strong spray of water to dislodge them from the leaves. Alternatively, insecticidal soap and neem oil can also be used to control them.
Mealybugs are small white insects that also feed on the plant's sap and produce honeydew. These pests can be managed by wiping them off with a cotton swab dipped in alcohol or by using insecticidal soap or neem oil.
Scale insects are small flattened insects that attach themselves to the plant's leaves and stems. These pests can be controlled by wiping them off with a cotton swab dipped in alcohol or by using neem oil.
Caterpillars are the larvae of moths and butterflies that feed on the plant's leaves, causing defoliation and weakening the plant. To manage caterpillars, it is advisable to handpick them and dispose of them safely. Bacillus thuringiensis (Bt) can also be used to control caterpillars.
Overall, proper cultural practices such as regular pruning, watering, and fertilizing can help keep Psydrax horizontalis healthy and resilient to pests and diseases.
