Overview
Rothmannia giganthosphaera K.Schum. ex Fagerl. is a species of flowering plant in the family Rubiaceae. It is a rare and unusual plant, native to the tropical rainforests of West and Central Africa. The plant is known for its large, showy flowers, which have a sweet fragrance and are pollinated by bats.
Common Names
The plant is commonly known as the Giant-fruit rothmannia or the African Gardenia.
Appearance
Rothmannia giganthosphaera K.Schum. ex Fagerl. is a slow-growing, evergreen tree that can reach up to 25m tall in the wild. The tree has a straight, tall trunk with smooth, brown bark. The leaves are shiny, dark green, and elliptical in shape, measuring up to 20cm long and 10cm wide. The flowers are large, measuring up to 10cm in diameter, with broad white petals and a bright yellow center. The fruit is a large, spherical berry, measuring up to 15cm in diameter, with a hard, woody shell that splits open when ripe to reveal a mass of small, edible seeds.
Uses
Rothmannia giganthosphaera K.Schum. ex Fagerl. is valued for its ornamental qualities and is often grown as a specimen tree in parks and gardens. The large, showy flowers are particularly prized and are used to make perfume. The fruit is also edible and is eaten by local people in Africa. In traditional medicine, various parts of the tree are used to treat a range of ailments.
Light Requirements
Rothmannia giganthosphaera K.Schum. ex Fagerl. requires bright but indirect light. It is best to place the plant near an east-facing window where it can receive bright morning light but avoid the harsh afternoon sun.
Temperature Requirements
This plant prefers warm temperatures ranging from 20°C to 25°C during the day and 15°C to 20°C at night. It can tolerate slightly cooler temperatures, but it should not be exposed to temperatures below 10°C.
Soil Requirements
The soil should be well-draining and rich in organic matter. A mixture of peat moss, perlite, and vermiculite is ideal for this plant. The pH level of the soil should be between 6.0 and 7.0.
Cultivation methods for Rothmannia giganthosphaera K.Schum. ex Fagerl.
Rothmannia giganthosphaera K.Schum. ex Fagerl., commonly known as the forest bell bush, can be cultivated outside as an ornamental plant in subtropical and tropical regions. The plant thrives in partial to full shade with well-draining soil. It prefers areas with high humidity and rainfall, making it a perfect plant for cultivating in tropical rainforests.
Watering needs for Rothmannia giganthosphaera K.Schum. ex Fagerl.
The plant requires regular watering. However, it is crucial not to overwater the plant, as it can lead to root rot. The soil should be kept moist at all times, but not too wet. The frequency of watering depends on various factors such as the weather, the size of the plant, the pot's size, and the type of soil. Therefore, it is essential to monitor the plant frequently to determine when to water it.
Fertilization of Rothmannia giganthosphaera K.Schum. ex Fagerl.
The forest bell bush requires adequate fertilization to grow well. It would be best to fertilize the plant using a balanced fertilizer rich in nitrogen, phosphorus, and potassium. It would be best to fertilize the plant during spring and summer when it's actively growing. However, it is necessary not to over-fertilize, as it can lead to leaf burn and impact the plant's health. Therefore, it is recommended to follow the manufacturer's instructions on the fertilizer's application and schedule.
Pruning Rothmannia giganthosphaera K.Schum. ex Fagerl.
Pruning is required for maintaining the plant's shape and controlling its growth. It is recommended to prune the plant at the beginning of the growing season. You can prune the plant to remove any diseased or damaged parts. You can also prune to control the plant's size. It would be best to use sterile pruning tools to prevent the spread of diseases.
Propagation of Rothmannia giganthosphaera K.Schum. ex Fagerl.
Rothmannia giganthosphaera K.Schum. ex Fagerl. can be propagated by several methods. The most common methods are through seed propagation, stem cuttings, and air layering.
Seed Propagation
Seeds of Rothmannia giganthosphaera K.Schum. ex Fagerl. can be collected from the plant when the fruit is ripe. The seeds should be cleaned from the fruit pulp and dried properly before sowing. The seeds can be sown directly into the soil mixed with sand or in germination trays filled with a mixture of peat and sand. The seeds should not be buried deep into the soil, and the soil should be kept moist. Germination usually takes place within two to four weeks.
Stem Cuttings
Propagation through stem cuttings is the quickest and easiest method to obtain clones of Rothmannia giganthosphaera K.Schum. ex Fagerl. The stem cuttings should be taken during the growing season and should include two to three nodes. The leaves should be removed from the bottom half of the cutting, and a rooting hormone should be applied to the cut end. The cuttings can be planted directly into a well-draining soil mix or in a mixture of peat and sand. The cuttings should be kept moist but not waterlogged. Roots should form in approximately 4 to 6 weeks.
Air Layering
Air layering is a propagation technique that involves encouraging roots to grow on a stem while it is still attached to the parent plant. For Rothmannia giganthosphaera K.Schum. ex Fagerl., air layering should be done during the growing season. A section of the stem should be chosen, and a 1-inch wide strip of bark should be removed from the stem. The exposed area should be treated with a rooting hormone, and moist sphagnum moss should be wrapped around the wounded area. The moss should be covered with a plastic bag and tied securely at the top and bottom. Once roots have formed in the moss, the entire section can be removed from the parent plant and planted into a well-draining soil mix.
Disease and Pest Management for Rothmannia giganthosphaera K.Schum. ex Fagerl.
Rothmannia giganthosphaera K.Schum. ex Fagerl. is a plant species that is relatively resilient to pests and diseases. However, there are still common issues that affect this plant that can be managed using various methods.
Common Diseases
One of the most common diseases that affect Rothmannia giganthosphaera is root rot. Root rot is caused by fungi that infect the roots of plants, leading to decay and death of the plant. The best way to prevent root rot is to ensure that the soil is well-draining and that the plant is not overwatered. Another disease that affects Rothmannia giganthosphaera is powdery mildew, a fungal disease that affects the foliage of plants. The best way to manage powdery mildew is to regularly prune any infected leaves and to promote good air circulation around the plants.
Common Pests
The most common pests that affect Rothmannia giganthosphaera are aphids and mealybugs. These pests feed on the plant sap, which can weaken the plant over time. To manage aphids and mealybugs, you can encourage natural predators like ladybugs or use insecticidal soaps or oils. Additionally, spider mites may also pose a problem as they feed on the plant's sap, causing the leaves to become yellow and spotted. You can manage spider mites through regular pruning and using insecticidal soap or neem oil.
Overall, Rothmannia giganthosphaera is relatively resistant to pests and diseases. However, if you notice any signs of infestation or disease, it is crucial to take action quickly to prevent the problem from becoming severe. Proper maintenance practices like pruning and watering can also help in preventing pest and disease infestations.
