Overview:
Aspalathus acuminata Lam. var. subinermis E.Mey. is a species of evergreen shrub belonging to the Fabaceae family. The plant is indigenous to South Africa and is commonly found in the Western Cape, particularly on the Cape Peninsula.
Appearance:
The shrub can grow up to 1.5m tall and has slender woody stems with sharp-tipped leaves. The leaves are green and delicate with an elongated shape, measuring up to 2cm in length. The small yellow flowers are grouped in clusters and bloom from July to November.
Common Names:
The plant is commonly known as needle-leaved rooibos or subspinescent rooibos in English. In Afrikaans, it is referred to as naaldblaar-rooibos or subgedoornde-rooibos.
Uses:
The leaves of Aspalathus acuminata Lam. var. subinermis E.Mey. have been used traditionally to make herbal tea similar to the well-known rooibos tea. The tea made from this plant has a pleasant taste and is caffeine-free, making it a great alternative to regular tea or coffee. Additionally, the plant's leaves have been used for their medicinal properties, including treating stomach illnesses, skin irritations, and inflammation.
Light Requirements
Aspalathus acuminata Lam. var. subinermis E.Mey. requires full sunlight for optimal growth and production. The plant requires at least 6 hours of uninterrupted sunlight exposure in a day. Inadequate lighting may result in poor growth and yield. It is, therefore, recommended to plant the crop in open areas or expose the plants to maximum sunlight exposure through pruning and trimming of surrounding trees and shrubs.
Temperature Requirements
Aspalathus acuminata Lam. var. subinermis E.Mey. prefers warm temperatures and can thrive in temperatures averaging between 20°C and 30°C. Extreme temperatures beyond the preferred range may negatively impact the plant growth and yield. In case of harsh temperatures, it is advised to provide artificial shade to the plants to avoid excessive heat and reduce the risk of water loss through transpiration.
Soil Requirements
The plant is generally tolerant to a wide range of soils and prefers well-drained soils with a neutral to slightly acidic pH. Soils that are too acidic or alkaline should be avoided as it may result in nutritional imbalances and stunted growth of the plant. Organic matter can also be added to improve soil fertility and increase water-holding capacity.
Cultivation Methods
Aspalathus acuminata Lam. var. subinermis E.Mey. is commonly grown by seed indoors in the spring or directly in the garden after the last frost. The plant prefers well-drained, acidic soil with a pH between 4.5 and 6.0. It is essential to choose a location that receives full sunlight and has protection from the wind. To ensure successful germination, plant seeds at a depth of 1.5 to 2 times the diameter of the seed. Keep the soil moist and warm until germination occurs, which takes about two to three weeks.Watering Needs
Aspalathus acuminata Lam. var. subinermis E.Mey. requires moderate watering, and the soil should never be allowed to dry out completely. Water the plant when the top inch of soil is dry to the touch, which is usually once a week or more frequently during hot, dry weather. However, overwatering should be avoided, as it can lead to root rot.Fertilization
Aspalathus acuminata Lam. var. subinermis E.Mey. is a leguminous plant and is capable of fixing nitrogen from the atmosphere. Therefore, it does not require significant fertilizer applications. However, a light application of balanced fertilizer with an N-P-K ratio of 5-10-5 during the growing season can help promote growth and flowering.Pruning
Pruning is not necessary for Aspalathus acuminata Lam. var. subinermis E.Mey., but it can help to promote a more compact and bushy growth habit. The best time to prune is in late winter or early spring before new growth begins. To prune, simply trim back any overgrown or leggy growth, removing up to one-third of the plant's overall size. This will help to promote more bushy growth and encourage the plant to produce more flowers.Propagation of Aspalathus acuminata Lam. var. subinermis E.Mey.
Aspalathus acuminata Lam. var. subinermis E.Mey. can be propagated through seeds or cuttings. Both methods have been successfully used to establish new plants, but each has its own advantages and disadvantages.
Propagation through seeds
Seeds of Aspalathus acuminata Lam. var. subinermis E.Mey. can be sown directly in the field or in pots in a greenhouse. Seeds should be washed and then soaked in water for 24 hours before sowing to stimulate germination. The best time for sowing is during the spring or early summer, as the plant is dormant during the winter months.
The seeds should be sown in a well-drained medium, preferably mixed with sand. When grown in pots, the seedlings should be transplanted to their permanent location after 4 to 6 months. When grown in the field, the seedlings should be thinned out to a spacing of 30 to 60 cm between plants.
It should be noted that Aspalathus acuminata Lam. var. subinermis E.Mey. has a low germination rate, and that the seedlings may take up to 3 years to reach maturity.
Propagation through cuttings
Propagation through cuttings is a quicker and more reliable method of propagating Aspalathus acuminata Lam. var. subinermis E.Mey. than propagation through seeds. Cuttings should be taken from softwood or semi-hardwood in the spring or early summer.
The cuttings should be 5 to 10 cm in length and should be taken from the top of the plant. The cuttings should be treated with a rooting hormone and then planted in a well-drained medium, preferably mixed with sand. The planting medium should be kept moist and the cuttings should be protected from direct sunlight for the first few weeks.
The cuttings should develop roots within 3 to 4 weeks, and can be transplanted to their permanent location after 4 to 6 months.
Disease Management
Aspalathus acuminata Lam. var. subinermis E.Mey. is generally a hardy plant that is not prone to many diseases. However, there are a few diseases that may affect the crop, and it is essential to take measures to mitigate their spread. These diseases include:
- Root rot: This disease is caused by fungi and is more prevalent in poorly drained soils. Infected plants may exhibit wilting, stunted growth, and yellowing of leaves. To manage root rot, it is essential to ensure that the soil is well-drained and to avoid overwatering.
- Grey mould: This disease is caused by the fungus Botrytis cinerea and is prevalent in wet and damp conditions. It causes the plant to rot and may lead to the death of the entire plant. To manage grey mould, it is essential to spray the plants with fungicides regularly and to ensure adequate air circulation around the plants.
- Virus infections: This disease may cause mosaic patterns on leaves, stunted growth, and leaf curling. There is no cure for viral infections. Therefore, it is essential to prevent the spread of the disease by using virus-free seeds and plants and to avoid sharing tools between infected and uninfected plants.
Pest Management
Like diseases, pests may affect the yield and health of Aspalathus acuminata Lam. var. subinermis E.Mey. It is essential to take steps to manage them. Common pests that may affect the plant include:
- Red spider mites: These tiny pests suck sap from the leaves of the plant, causing them to become yellow and eventually die. To manage red spider mites, it is essential to use miticides and to ensure that the plant is adequately hydrated to prevent dry conditions that favor the pests.
- Coffee white stem borer: These pests bore into the plant's stem, causing extensive damage and reducing the yield. To manage coffee white stem borer, it is essential to use insecticides and to prune and burn infected stems to prevent the spread of the pests.
- Thrips: Thrips suck sap from the leaves, causing them to turn pale and silvery. The pests also cause distortion and shedding of flowers. To manage thrips, it is essential to use insecticides and to practice proper crop hygiene to prevent the spread of the pests.
In conclusion, managing pests and diseases is crucial in ensuring that Aspalathus acuminata Lam. var. subinermis E.Mey. crops thrive and produce a high yield. It is essential to use preventative measures, such as planting healthy seeds and plant material, ensuring proper hygiene, and providing a favorable environment for the plant's growth, to minimize the risk of pests and diseases affecting the crop.
