Overview:
Rhus rosmarinifolia Vahl var. stenophylla (Eckl. & Zeyh.) Schönland, commonly known as the narrow-leaved karree, is a small tree or shrub that belongs to the sumac family. It is native to southern Africa and widely distributed in the Cape Province.
Appearance:
It is a small tree or shrub that grows up to 4 meters in height and 3 meters in width. Its leaves are thin, narrow, and elongated, resembling the leaves of the rosemary plant. The leaves are green in color and become reddish-brown during autumn. The tree produces small, greenish-white flowers in late summer, followed by reddish-brown fruits that resemble berries. The fruits are highly acidic and not edible.
Uses:
The narrow-leaved karree has several uses. The tree is often planted for ornamental purposes in gardens, parks, and along streets. It is also used to stabilize soil and prevent erosion. The bark of the tree is used to make a decoction in traditional medicine to treat stomach ailments, diarrhea, and dysentery. The tree is also used as a source of firewood and charcoal.
Common Names:
The narrow-leaved karree has several common names, including borkumwood, karree, wild tamarisk, and wild teak.
Light Requirements
Rhus rosmarinifolia Vahl var. stenophylla thrives in full sun to partial shade, preferring areas where it can receive at least six hours of direct sunlight each day. Although it can survive in low light conditions, it may not flower or grow to its fullest potential.
Temperature Requirements
This plant is generally hardy and can tolerate a range of temperatures. It can withstand hot, dry conditions but prefers cooler temperatures around 60-75°F (15-24°C). It can also tolerate occasional frost and temperatures as low as 20°F (-6°C) but cannot survive in extremely cold conditions.
Soil Requirements
Rhus rosmarinifolia Vahl var. stenophylla is adaptable to different soil types but prefers well-draining soils that are slightly acidic with a pH range between 5.5 to 7.5. It can tolerate poor soils but not waterlogged soils. Adding organic matter to the soil can help improve its fertility and moisture retention.
Cultivation Methods for Rhus rosmarinifolia Vahl var. stenophylla
Rhus rosmarinifolia Vahl var. stenophylla is a hardy plant that thrives in warm and arid regions. It is best grown in well-drained, sandy soil with a pH range of 6.5-7.5. The plant requires full sun exposure to grow and develop fully. It can withstand temperature extremes ranging from -2°C to 45°C, and it grows well in harsh and dry climates. The plant can be grown from seeds or cuttings.
Watering Needs for Rhus rosmarinifolia Vahl var. stenophylla
The watering needs of Rhus rosmarinifolia Vahl var. stenophylla are low to moderate. Overwatering can lead to root rot, so it is crucial to let the soil dry out between watering intervals. The ideal watering frequency for this plant is once every 10-14 days during the growing season. During the dormant period, reduce watering to once every 3-4 weeks.
Fertilization for Rhus rosmarinifolia Vahl var. stenophylla
The plant requires minimal fertilization, and too much fertilizer can lead to excessive growth at the expense of the plant's health. The recommended fertilizer is a slow-release granular fertilizer with an NPK ratio of 10-10-10 applied during the growing season. Apply the fertilizer towards the end of the rainy season or early spring.
Pruning for Rhus rosmarinifolia Vahl var. stenophylla
Pruning is essential to maintain the plant's shape and health. The best time to prune is during the dormant period when the plant is less susceptible to damage. Remove any dead or damaged branches or branches that are growing inwards towards the center of the plant. Avoid pruning more than one-third of the plant's foliage to prevent stress.
Propagation of Rhus rosmarinifolia Vahl var. stenophylla (Eckl. & Zeyh.) Schönland
Rhus rosmarinifolia Vahl var. stenophylla (Eckl. & Zeyh.) Schönland, commonly known as the narrow-leaved karree, is a hardy, evergreen shrub that can grow up to 2 meters tall and 1.5 meters wide. It is native to South Africa and is commonly found in dry areas such as the Karoo.
There are several methods of propagating Rhus rosmarinifolia Vahl var. stenophylla, including:
Seed Propagation
Seed propagation is the most common method of propagating Rhus rosmarinifolia Vahl var. stenophylla. The seeds are collected from the plant when the fruits are mature and ripe. The fruits are usually collected in autumn, and the seeds are then extracted and stored in a cool, dry place until planting.
The seeds should be planted in a well-draining soil mix, with a layer of fine sand on top to help with germination. The seeds should be watered regularly, but care should be taken not to overwater as this can lead to rotting.
The seeds usually germinate within 4-8 weeks, and once they are large enough, they can be transplanted into individual pots or planted directly into the ground.
Cutting Propagation
Cutting propagation can also be used to propagate Rhus rosmarinifolia Vahl var. stenophylla. The best time to take cuttings is in the spring when the new growth is starting to appear.
The cuttings should be taken from the tips of the branches and should be about 5-10cm long. The leaves should be removed from the bottom half of the cutting, and the cutting should be dipped in rooting hormone to help with root development.
The cuttings should be planted in a well-draining soil mix, with a layer of fine sand on top to help with root development. The cuttings should be watered regularly, but care should be taken not to overwater as this can lead to rotting.
The cuttings usually root within 4-6 weeks, and once they have developed a good root system, they can be transplanted into individual pots or directly into the ground.
Disease Management
One of the common diseases that affect Rhus rosmarinifolia var. stenophylla is leaf spot, caused by the fungus Phyllosticta rhamnicola. This disease causes the leaves to develop small, circular, light brown spots, which enlarge and merge to form larger blotches that may cause premature leaf drop. To manage this disease, remove the affected leaves and dispose of them properly. Also, avoid overhead watering to minimize the spread of the fungus.
Anthracnose is another fungal disease that may affect Rhus rosmarinifolia var. stenophylla. It often affects the leaves and twigs, causing irregular-shaped dark brown spots. The disease may spread rapidly, leading to defoliation. To manage this disease, ensure proper sanitation practices such as removing and destroying debris around the plant. Proper pruning can also help reduce the spread of the disease.
Pest Management
One of the most common pests that affect Rhus rosmarinifolia var. stenophylla is the spider mite. These pests cause yellowing and browning of the leaves, which may lead to defoliation. To control spider mites, avoid dust and provide adequate water to the plant. If the infestation is significant, consider using insecticidal soap or horticultural oil, sprayed on the underside of the leaves.
Another common pest of Rhus rosmarinifolia var. stenophylla is the scale insect, which can cause the leaves to turn yellow or develop brown spots. Scales can be controlled using insecticidal soaps, horticultural oils, and neem oil. Additionally, pruning affected parts of the plant and disposing of them properly can reduce the spread of scale insects.
