Overview
Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern. is a species of shrub in the Anacardiaceae family, which is commonly known as the African sumac. It is native to southern Africa, particularly in South Africa and Namibia. The plant has a number of traditional medicinal uses.
Appearance
The African sumac is a deciduous to evergreen shrub that can grow up to 3 meters tall. It has a multi-branched, spreading habit, with a rough, greyish bark. The stems and leaves are covered in fine hairs. The leaves are pinnate, with numerous small leaflets arranged along the stem, and can vary in size depending on the subspecies. The flowers are small and greenish-yellow, arranged in dense clusters at the tips of the branches. The fruit of the African sumac is a small, spherical drupe that is reddish-brown in color.
Uses
The African sumac has a number of traditional medicinal uses. The leaves and bark of the plant are used to treat ailments such as diarrhea, dysentery, and fevers. The juice of the plant is also used as a treatment for snake bites and insect stings. In addition to these medicinal uses, the African sumac is also sometimes used for its timber. The wood is hard and durable, and is used for making furniture, tool handles, and other items that require a strong, sturdy wood.
Light requirements
Rhus montana Diels var. gerrardii grows best in partial shade to full sun. It tolerates both direct and indirect sunlight. However, it is important to note that too much direct exposure to sunlight may cause leaf scorching, especially during hot summers.
Temperature requirements
The plant is known to thrive in a cool environment with temperatures ranging from 8°C to 18°C. It can withstand frost, but it does not grow well in excessive heat. Temperatures higher than 25°C may cause the plant to wilt, especially if it has not been adequately watered.
Soil requirements
Rhus montana Diels var. gerrardii thrives in well-draining soil with a pH ranging from neutral to slightly acidic. A sandy loam mixture providing good aeration is ideal. The plant is intolerant to saline soils, and the high salt content can lead to poor growth and even death if not corrected.
Cultivation Methods
Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern. is a hardy shrub that grows well in many soil types. It prefers a well-draining soil with a pH between 6.0 and 7.5 and full sun to partial shade. Plant in the early spring or fall when temperatures are mild to establish the root system. Plant individual shrubs six feet apart to allow for growth.
Watering Needs
Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern. requires moderate watering during its establishment period. Once established, this shrub is relatively drought-tolerant and needs watering only during prolonged dry spells. Water at the base of the plant to avoid wetting the foliage, which can cause problems like powdery mildew.
Fertilization
Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern. does not require regular fertilization. However, a light feeding of a balanced fertilizer in early spring can be beneficial. Avoid applying fertilizer late in the growing season, which can cause young growth that is susceptible to damage from frost.
Pruning
Prune Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern. in late winter or early spring by removing damaged, diseased, or dead wood. Shape the shrub to maintain a natural form and size. It's important to wear gloves and protective clothing when handling this plant as it can cause skin irritation due to its sap. Do not prune during the growing season, as this can stimulate new growth that is susceptible to damage from frost.
Propagation of Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern.
Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern. is a shrub that is commonly propagated by seed and cuttings.
Propagation by Seed
Propagation by seed is the most common and easiest method of propagating Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern. Seeds are collected from mature fruits in late autumn and sown in spring.
The seeds are sown in seed trays or pots containing a mixture of compost and sand or vermiculite at a depth of 1cm. The pots or trays are then placed in a warm place with constant moisture. Germination typically occurs within 3 to 4 weeks.
Once the seedlings have grown large enough, they can be transplanted into bigger pots or into the ground. It is best to plant the seedlings when they are still small, as they have brittle roots that can be easily damaged when transplanting.
Propagation by Cuttings
Propagation by cuttings is also a viable method of propagating Rhus montana Diels var. gerrardii (Harv. ex Engl.) R.Fern. Cuttings can be taken from mature branches in late summer or early autumn.
The cuttings should be around 10-15cm long and taken from the tips of the branches. The leaves on the lower half of the cutting should be removed, and the cutting should be rusted overnight in powdered rooting hormone.
The cuttings should then be planted in small pots or trays containing a mixture of compost and sand or vermiculite. The pots or trays should be placed in a warm place with consistent moisture. Rooting usually takes around 4-6 weeks.
Once the cuttings have rooted, they can be transplanted into bigger pots or into the ground. It is best to plant the cuttings when they are still small, as they have brittle roots that can be easily damaged when transplanting.
Disease Management
Rhus montana Diels var. gerrardii, commonly known as Gerrard's sumac, is generally resistant to most diseases; however, there are few fungal and bacterial infections that can affect this plant.
Fungal diseases: Powdery mildew and leaf spot caused by fungi can sometimes affect the plant. To manage these diseases, it is essential to maintain proper plant hygiene and sanitation. Prune and dispose of infected areas, and avoid overhead watering. Fungicides can also be used if required.
Bacterial diseases: Crown gall and bacterial leaf blight are the two bacterial infections that can affect Gerrard's sumac. There are no significant management strategies for bacterial diseases, and it is better to remove the infected plant parts.
Pest Management
Gerrard's sumac is not susceptible to many pests. However, certain insects and mites can infest the plant and cause damage.
Mites: Spider mites can damage the foliage and cause discoloration and webbing. To manage mite infestation, wash the leaves with a strong stream of water and, if required, use insecticidal soaps.
Lepidopteron larvae: Some butterfly and moth larvae can feed on the leaves of Gerrard's sumac. Caterpillars can be picked off by hand or treated with insecticides if the infestation is severe.
Aphids: Sometimes aphids can be found on the leave's underside, and if not managed, their populations can grow rapidly and cause damage. To manage aphids, wash the leaves with a strong stream of water or spray insecticidal soaps.
Regular monitoring of the plant for any signs of pest infestation and maintaining proper plant hygiene can help in managing pests infestation.
