Overview
Grewia carpinifolia Juss. var. rowlandii, also known as Rowland's grewia or Transvaal grewia, is a species of shrub or small tree that belongs to the family Malvaceae. This plant is native to southern Africa and is often used for medicinal and ornamental purposes.
General Appearance
The Rowland's grewia plant can grow up to 2.5 meters tall and 1.5 meters wide. It has a dense and round crown with a trunk that can have a diameter of up to 15 cm. The bark is brownish-grey and has a slightly rough texture. The leaves are simple, alternate, oval-shaped, and have serrated margins. They are usually 4-9 cm long and 3-6 cm wide. The flowers of this plant are small and yellowish-white, and they bloom from late winter to early spring. The fruits are small, almost spherical berries that are black or dark purple when fully ripe, and they contain small seeds.
Common Names
Rowland's grewia is also known by other common names such as African star, African cross-berry, and Wild syringa. In South Africa, it is also called "meelbessie" or "mealie-berry" due to the similarity of the taste of its fruit to that of roasted maize.
Uses
The Rowland's grewia plant has several medicinal and practical uses. The roots, bark, and leaves are used in traditional medicine to treat various diseases such as stomach problems, skin rashes, and infertility. The fruit is edible and can be consumed fresh or dried. It is rich in vitamin C and other nutrients, and it is often used to make jams, juices, and wine. The hard and durable wood of this plant is used for making furniture, tool handles, and other household items. In addition, the Rowland's grewia plant is also used as an ornamental plant in parks and gardens due to its attractive appearance and tolerance to a wide range of growing conditions.
Light Requirements
Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret grows best in bright but indirect sunlight. It is a species that can also tolerate partial shade. When grown indoors, it is recommended to place the plant at a bright, sunny window with a sheer curtain.
Temperature Requirements
The plant prefers warm temperatures ranging from 20°C to 30°C. It cannot tolerate frost and extremely cold temperatures. It is advisable to keep the plant at the temperature between 20°C to 25°C in winters. At higher temperatures, the plant may need to be watered more frequently to avoid the risk of dehydration.
Soil Requirements
Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret prefers well-draining soil that holds sufficient moisture. The soil should be rich in organic matter and should have neutral to slightly acidic pH. The plant can adapt to a wide range of soils, from sandy loams to red laterite soils, but it is essential to avoid waterlogged or poorly draining soils as these can cause root rot and other issues.
Cultivation Methods
Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret grows well in moist, well-draining soil and prefers full sunshine. The plant can propagate from seeds, cuttings, or stem plucking. The optimal temperature for the growth of this plant is between 27°C to 35°C.
It is better to plant the saplings in April. When transplanting or repotting the saplings, it is essential to ensure that the roots are not damaged. Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret also requires adequate spacing between the plants to promote good growth.
Watering Needs
Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret requires regular watering after planting and during the first three years of growth. The plant does well in areas with high rainfall, but dry conditions can also be suitable if the soil is moist. It is essential to ensure that the plant does not overwater, as this can lead to root rot or other fungal diseases.
Fertilization
For optimal growth and development, Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret requires adequate nutrients. Fertilizers that are rich in nitrogen, phosphorus, and potassium are ideal for this plant. The fertilization program should begin in spring, and it should last throughout the growing season.
It is essential to follow the manufacturer's instructions when applying the fertilizer. Overfertilization can lead to leaf burn and other detrimental effects, while underfertilization can lead to stunted growth or nutrient deficiency.
Pruning
Pruning is essential to promote good growth, flowering, and fruiting in Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret. The pruning should be done after the plant has finished flowering, and it should be performed with clean and sterile pruning tools.
The plant requires regular pruning to prevent dead, diseased, or damaged limbs from affecting the rest of the plant. It is also essential to prune the plant to promote airflow, which can prevent fungal diseases and pests from affecting the plant. If the plant is overgrown, it can also be beneficial to undertake moderate pruning to maintain its size and shape.
Propagation of Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret
Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret, commonly known as the Rowland's grewia, can be propagated by both sexual and asexual methods.
Sexual Propagation
Seeds of G. carpinifolia can be collected from ripe fruits and sown in well-drained soil. The best time for sowing is during early spring or at the beginning of the rainy season. Seeds should be sown in rows and covered with a thin layer of soil. Seedlings should emerge within 2-3 weeks and should be thinned out to prevent overcrowding. The optimum germination temperature for G. carpinifolia is around 25-30°C.
Asexual Propagation
G. carpinifolia can also be propagated by vegetative means such as stem cuttings and layering.
Stem Cuttings: Select a healthy stem from the mother plant that is free from diseases and pests. The stem should be about 15-20 cm in length and have at least 2-3 nodes. Remove the lower leaves and dip the cutting in rooting hormone powder. Plant the cutting in a well-drained mixture of sand and peat moss or any other suitable rooting medium. Water the cutting and keep it in a shaded area with high humidity. In about 4-6 weeks, roots will emerge, and the cutting can be transplanted to a larger container or directly in the garden.
Layering: Select a low hanging branch from the mother plant that is flexible enough to be bent towards the ground. Make a small wound on the branch and cover it with rooting hormone powder. Bury the wounded part of the branch in the soil and hold it in place with a U-shaped wire or any other suitable device. Water the buried branch regularly and keep it in a shaded area with high humidity. In about 8-10 weeks, roots will emerge from the buried part of the branch and can be separated from the mother plant.
Disease and Pest Management for Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret
Grewia carpinifolia Juss. var. rowlandii (K.Schum.) Burret is a shrub that is resistant to many pests and diseases. However, it is not entirely immune and may be susceptible to some common plant diseases and pests. The following are some of the diseases and pests that may affect this plant, and ways to manage them:
Diseases
Fungal leaf spot: This disease is caused by the fungus Cercospora grewiae, which produces brown spots on the leaves. These spots can grow and merge, causing premature leaf drop. To manage this disease, keep the plant healthy and free of stress. Avoid overhead watering, which can promote fungal growth. Remove any infected leaves and apply a fungicide as needed.
Root rot: Grewia carpinifolia Juss. var. rowlandii is susceptible to root rot caused by soil-borne fungi such as Phytophthora and Rhizoctonia. The symptoms of root rot include wilting, yellowing of leaves, and root decay. To manage this disease, avoid over-watering and make sure the soil is well-draining. Remove infected plants and treat the soil with a fungicide before replanting.
Pests
Aphids: These pests suck the sap from the leaves, causing them to wilt and curl. They can also transmit plant diseases. To manage aphids, spray the plant with a strong stream of water, which will knock them off the leaves. You can also use insecticidal soap or neem oil to control them.
Spider mites: These pests are tiny and can be difficult to detect. They can cause the leaves to turn yellow and have a browning appearance. To manage spider mites, spray the plant with water to remove dust and any webs that may be present. Use a miticide to control the infestation.
Scale insects: These pests are small and can be difficult to detect. They suck the sap from the leaves and can cause them to turn yellow and drop off the plant. They can also excrete a sticky substance called honeydew, which can attract ants. To manage scale insects, use a soft brush to remove them from the leaves or use insecticidal soap to control the infestation.
By following these disease and pest management tips, you can help keep your Grewia carpinifolia Juss. var. rowlandii healthy and thriving.
