Origin
Keetia zanzibarica (Klotzsch) Bridson subsp. zanzibarica, also known as the Zanzibar keetia, is a plant species of the Rubiaceae family that is native to Tanzania, Mozambique, and Angola.
Common Names
The Zanzibar keetia is also known by its common name, the "Bush Tea" plant, which refers to its leaves being used to make a caffeine-free herbal tea. In Tanzania, it is called "Mkunazi," and "Matawi ya Chai" in Swahili.
Uses
The leaves and roots of the Zanzibar keetia are widely used in traditional medicine to treat various ailments, including fever, headache, and digestive disorders. The plant's leaves are also used to make a herbal tea that is believed to have a calming effect and is used to relieve stress and anxiety. In addition, it is used as an aromatic ingredient in cooking and as a natural pesticide.
General Appearance
The Zanzibar keetia is a small to medium-sized shrub that can grow up to 3 meters tall. It has opposite leaves that are elliptic in shape and can grow up to 14 cm long and 7 cm wide. The leaves are dark green and shiny on the upper surface, while the lower surface is a lighter green color. The plant produces small white or yellow flowers that are clustered in groups of four or five. The fruit of the plant is a small, red berry that contains one or two seeds.
Light Requirements
Keetia zanzibarica requires bright, filtered light but it should not be exposed to direct sunlight. It can thrive well under full shade but may experience stunted growth with minimal fruiting. Therefore, it is recommended to place the plant in areas receiving filtered light for at least 6 hours a day.
Temperature Requirements
The plant grows well under warm and humid conditions. Ideal temperatures range from 20°C to 35°C, with a minimum of 10°C during the night. Temperatures below 10°C can harm the plant. It is worth noting that variations in temperature can affect fruit production, with flowering significantly reduced during times of low temperatures.
Soil Requirements
Keetia zanzibarica prefers well-drained soils with medium texture and high organic matter. A pH range of 5.5 to 6.5 is suitable for optimum growth and fruit development. The plant prefers soils with adequate moisture levels. The use of mulch or organic matter is recommended to retain moisture levels. In addition, the plant is sensitive to soil salinity; therefore, it is not recommended to plant it in highly saline soils.
Cultivation
Keetia zanzibarica (Klotzsch) Bridson subsp. zanzibarica is a tropical plant originating from East Africa's coastal forests. It thrives best in warm temperatures, high humidity, and partial sunlight. The plant is known to grow to a height of about 2-3 meters, and it is very easy to cultivate.
Watering Needs
Proper watering is crucial to the growth and development of Keetia zanzibarica. The plant requires regular watering, but it should not be overwatered to prevent root rot. It is best to water the plant when the top inch of soil is dry, and the water should be allowed to drain out of the bottom of the pot. The plant does not tolerate drought well and requires a constant supply of moisture to thrive.
Fertilization
Keetia zanzibarica requires frequent fertilization to achieve optimal growth and flowering. A balanced fertilizer, such as 10-10-10 or 20-20-20, can be applied every two weeks during the growing season (spring and summer). Fertilization should be stopped during the dormant season (fall and winter) to avoid overfeeding the plant.
Pruning
Regular pruning of Keetia zanzibarica helps to promote bushy growth and flowering. Pruning should be done at the beginning of the growing season (spring). Dead and damaged foliage should be removed as soon as noticed, and any overgrown branches should be pruned to maintain the desired shape and size. Pruning also promotes better air circulation around the plant, reducing the incidence of fungal diseases.
Propagation of Keetia zanzibarica (Klotzsch) Bridson subsp. zanzibarica
The Keetia zanzibarica (Klotzsch) Bridson subsp. zanzibarica plant can be propagated through several methods:
Seed propagation
Seeds are the most common way to propagate Keetia zanzibarica (Klotzsch) Bridson subsp. zanzibarica. The seeds can be obtained from a mature plant and should be planted as soon as possible to avoid dehydration. The seedlings emerge after a few weeks, and they can be transplanted into individual pots after about six months.
Cuttings propagation
Another method of propagation is through stem cuttings. Cuttings should be taken from a mature and healthy plant. The cutting should be around 10-15 cm in length, and it should be taken from the top of the plant. The leaves on the cutting should be removed, leaving only the top few leaves. The cutting should be planted in a potting mix and kept moist. Rooting occurs after 4-6 weeks, and the young plant can be transplanted into individual pots.
Air layering propagation
Air layering is a propagation method where a branch of the plant is stimulated to grow roots while still attached to the parent plant. This method is useful for propagating Keetia zanzibarica (Klotzsch) Bridson subsp. zanzibarica as it produces a new plant that is genetically identical to the parent plant. To air layer, a section of the branch is cut and treated with rooting hormone. The section is then wrapped with sphagnum moss and covered with plastic wrap or aluminum foil. Roots emerge from the moss after about six weeks, and the new plant can be cut and potted separately.
Disease Management
Keetia zanzibarica is generally resistant to diseases, but it can still be susceptible to certain fungal and bacterial infections. The most common diseases that might affect the plant are anthracnose, powdery mildew, leaf spot, and root rot.
In order to manage anthracnose, it is important to remove all infected plant parts and destroy them. The affected plant should also be treated with a fungicide. Powdery mildew can be prevented by ensuring adequate air circulation around the plant and avoiding overhead watering. Leaf spot can be managed by removing the affected plant parts and disposing of them properly. Using a fungicide is also recommended. Root rot can be prevented by ensuring proper drainage and not overwatering the plant.
Pest Management
Keetia zanzibarica may also be susceptible to pest infestations, including mealybugs, spider mites, and scale insects.
To manage mealybugs, it is recommended to physically remove them with a cotton swab or by spraying the plant with a mixture of water and dish soap. Spider mites can be prevented by regularly misting the plant to increase humidity and spraying with an insecticidal soap. Scale insects can be managed by removing them with a cotton swab or spraying with a horticultural oil.
It is important to monitor the plant regularly for signs of pests and diseases and to address any issues promptly to prevent them from spreading to other plants.
