Overview
Rhus horrida Eckl. & Zeyh., commonly known as Cape sumac, is a shrub or small tree belonging to the Anacardiaceae family. It is native to the southwestern regions of Africa, including South Africa, Lesotho, and Zimbabwe.
Appearance
Cape sumac typically grows up to a height of 3-4 meters and has a spreading habit. Its branches are often drooping and tend to sprawl over the ground. The plant has glossy green pinnate leaves that are 20-30 cm long, with a serrated margin. In autumn, its leaves turn a bright red or orange colour, which is a beautiful sight to behold. The flowers of Cape sumac are small, greenish-white, and appear in late spring to early summer. The fruits of the plant are red, velvety, and resemble small berries.
Uses
The leaves, bark, and roots of Cape sumac have a long history of use in traditional medicine. They are used to treat a variety of ailments, including fever, stomach ailments, and respiratory problems. The plant also has several culinary uses. Its berries, which are sour and acidic, are used to make a condiment similar to sumac spice. The leaves of the plant can be used to brew a tea that is high in Vitamin C, and the bark can be used to dye textiles. The plant is also a popular ornamental shrub and is often grown in gardens for its attractive foliage and vibrant autumn colours.
Overall, Rhus horrida Eckl. & Zeyh. is a versatile plant that has both medicinal and culinary uses. Its striking appearance makes it a popular choice for ornamental gardening as well.Light Requirements
Rhus horrida Eckl. & Zeyh. thrives in full sun to partial shade conditions. For optimal growth and development, it is suggested to provide at least 6 hours of direct sunlight daily. Insufficient light causes the plant to become leggy and weak, making it susceptible to pest and disease infestations. On the other hand, excessive sunlight could lead to sunscald and other related problems.
Temperature Requirements
The Rhus horrida Eckl. & Zeyh. is native to South Africa and can tolerate a wide range of temperatures. The plant can grow in low winter temperatures, is drought-resistant, and can survive high summer temperatures. It can withstand frost and can grow well in conditions where the minimum temperature is 5 °F (-15 °C) and the maximum temperature can reach up to 104 °F (40 °C). However, it is always suggested to offer it protection in regions with extreme temperature fluctuations.
Soil Requirements
Rhus horrida Eckl. & Zeyh. flourishes in well-draining, moist soil. The soil should not be waterlogged and have good aeration to allow air to reach the roots. A slightly acidic to slightly alkaline soil pH range of 5.5-7 is ideal. The plant can grow well in a variety of soil types, including clay, loam, and sandy soils. It also requires regular fertilization during growth and flowering periods to maintain optimal health and productivity.
Cultivation Methods
Rhus horrida Eckl. & Zeyh., commonly known as the red currant, is a hardy shrub that prefers well-drained soil and a sunny position. It can be propagated from seed or through hardwood cuttings taken in winter or early spring. Ensure the soil is rich in organic matter, and keep the plant well-watered during the first year.
Watering Needs
Rhus horrida Eckl. & Zeyh. prefers evenly moist soil, but avoid overwatering as it can lead to root rot. Water the plant deeply once a week during the growing season, but reduce watering during the winter months when growth slows down.
Fertilization
Apply a balanced fertilizer in early spring before new growth appears. Use a slow-release fertilizer that will release nutrients gradually throughout the growing season. Avoid using high-nitrogen fertilizers, as they can encourage excessive leaf growth at the expense of fruiting.
Pruning
Prune Rhus horrida Eckl. & Zeyh. in late winter or early spring before new growth appears. Remove any dead, damaged, or diseased growth, and thin out any overcrowded branches to improve airflow and sunlight exposure. Shorten back the remaining branches by about a third to encourage vigorous new growth and fruiting.
Propagation of Rhus horrida Eckl. & Zeyh.
The Rhus horrida Eckl. & Zeyh., commonly known as the Cape Rhus, is a resilient plant that is relatively easy to propagate. The plant can be propagated sexually or asexually.
Sexual propagation
Sexual propagation involves planting seeds from the plant. The seeds are viable and can be sourced from mature fruits. To prepare the seeds for planting, they should be soaked in water for 24 to 48 hours to soften the seed coat and initiate germination. Once soaked, the seeds can be planted in a well-draining soil mix, kept moist and in a shaded area. The seeds will germinate within 2 to 3 weeks.
Asexual propagation
Asexual propagation can be achieved through stem cuttings or layering. Stem cuttings should be taken from the parent plant, ensuring that the cutting is not too young or too old. The cutting should be about 10 to 15 cm long, stripped of its leaves, except for the top set of leaves. The cutting can be dipped in rooting hormone powder and planted in a moist and well-draining soil mix. It should be kept in a shaded area until rooting occurs. The cutting will root within 3 to 4 weeks.
For layering, a low-lying branch of the parent plant is bent to the ground and pinned down with a stake. The branch can be slit open on its underside to expose a section of the cambium layer. The exposed section can be covered with soil, and the branch secured in place. The branch will develop roots at the exposed section. Once rooted, the branch can be separated from the parent plant and transplanted.
Disease and Pest Management for Rhus horrida Eckl. & Zeyh.
Rhus horrida Eckl. & Zeyh., commonly known as the stink bush, is a hardy plant that is relatively pest-free and disease resistant. However, it can still be vulnerable to some pests and diseases, especially if conditions are not optimal.
Common Diseases:
Bacterial Leaf Spot: This disease is caused by the bacterium Xanthomonas campestris, and it manifests as small, water-soaked spots on leaves that eventually turn brown and fall off. Bacterial leaf spot can spread rapidly and can be difficult to control. To manage this disease, infected plant parts should be removed and destroyed, and the use of fungicides or copper sprays can be helpful.
Leaf Blight: Caused by the fungus Cylindrosporium rhus, leaf blight manifests as brown spots with gray centers on leaves. As the disease progresses, the leaves may drop prematurely. Fungicides can be applied to manage this disease, and sanitation practices such as removing diseased plant parts can also help prevent the spread.
Common Pests:
Rhus Gall Mite: The Rhus gall mite is a common pest of Rhus horrida. It manifests as small galls on leaf margins and stems, which can cause the leaves to curl and distort. To manage this pest, infected plant parts should be removed and destroyed, and the use of insecticidal soaps or horticultural oils can be helpful.
Spider Mites: Spider mites are very small and hard to detect, but they can cause significant damage to Rhus horrida by sucking sap from leaves. The first signs of infestation are typically small, yellow speckles on the leaves. To manage this pest, the use of insecticidal soaps or horticultural oils can be helpful, and spraying the plant with a strong stream of water can help knock off the mites.
Overall, regular monitoring and maintenance of Rhus horrida can help prevent and manage both disease and pest issues. Providing optimal growing conditions such as well-drained soil and appropriate watering can also help keep the plant healthy and resilient.
