Origin and Common Names
Acacia welwitschii Oliv. subsp. welwitschii is a species of flowering plant belonging to the family Fabaceae. It is commonly referred to as Welwitschia's Acacia, Welwitsch's Acacia, or Wawasa. It is native to Angola, Namibia, and Zambia.
Appearance
The Welwitschia's Acacia is a deciduous shrub or small tree that can grow up to 6 meters tall. The bark is a light grey-brown color and the tree has a rounded crown. The leaves are compound with 2-4 pairs of pinnae. The pinnae are covered with white or golden hairs on both surfaces and end in a sharp point, with a length of up to 10 cm. The flowers are yellow or cream-colored, and are produced in solitary or in pairs on axillary spikes that are up to 5 cm long.
Uses
Acacia welwitschii Oliv. subsp. welwitschii has various uses. Its fruit and bark are used in traditional medicine to treat various illnesses including malaria, fever, and diarrhea. The tree is also a source of gum, which can be used in the production of cosmetics, adhesives, and watercolor paints. Additionally, the tree is used as fuelwood and provides a valuable source of timber for furniture and construction.
Growth Conditions of Acacia welwitschii Oliv. subsp. welwitschii
Acacia welwitschii Oliv. subsp. welwitschii is a hardy, medium-sized tree that can grow up to 15 meters tall. It is native to Angola, Namibia, and Zambia. It is a deciduous tree with attractive foliage and fragrant, yellow flowers.
Light
Acacia welwitschii requires full sunlight to grow properly. It can tolerate some shade but grows best in areas with direct sunlight. The plant can grow in hot, dry conditions, but it requires ample water and shade during extremely hot periods. In areas with insufficient sunlight, the tree's growth can be stunted, and it may not produce flowers or fruit.
Temperature
The plant requires warm temperatures to grow correctly. It can tolerate high temperatures of up to 40 degrees Celsius but prefers temperatures between 20 and 30 degrees Celsius. In areas with colder temperatures, the plant can survive, but its growth will be slower, and it may not produce flowers or fruit.
Soil Requirements
The plant is adapted to grow in sandy and rocky soils with low fertility. However, it grows best in well-draining soils with a pH range of 5.5 to 7.5. The soil must also be rich in organic matter, and the plant must be fertilized regularly to maintain healthy growth. Additionally, the tree does not tolerate waterlogged or poorly drained soils and requires adequate drainage.
Cultivation Methods
The Acacia welwitschii Oliv. subsp. welwitschii, also known as Welwitschia acacia or Sphaeralcea acacia, is indigenous to Angola and Namibia. It is a drought-tolerant plant, and it can survive with very little water. It is best suited for regions with low rainfalls or those with arid climates. When cultivating the Acacia welwitschii Oliv. subsp. welwitschii, ensure that the soil is well-drained and porous. It is essential to plant the saplings in early spring or fall when the soil is warm, and there is plenty of sunshine.
Watering Needs
The Acacia welwitschii Oliv. subsp. welwitschii does not require much water. It is best to water this plant regularly but sparingly. When watering, ensure that the soil is thoroughly soaked and that the water seeps to the root system. Avoid getting the leaves wet, particularly during the winter season, as this may lead to fungal infections or leaf drop. During the dry season, reduce watering to once per month or reduce it further, depending on the specific climatic conditions in your area.
Fertilization
The Acacia welwitschii Oliv. subsp. welwitschii does not require much fertilizer. Before planting, it is advisable to incorporate organic fertilizer such as well-rotted manure or compost into the soil. This helps to provide sufficient nutrients for the plant's growth. After planting, the plant requires little to no fertilizer. If necessary, apply a slow-release fertilizer during the growing season, but remember to follow the manufacturer's instructions carefully.
Pruning
The Acacia welwitschii Oliv. subsp. welwitschii does not require much pruning. However, it is advisable to remove any dead or diseased branches. You can also remove any unwanted growth or shape the plant to your desired form. However, it is important to note that this plant is sensitive to pruning, and excessive cutting may cause significant damage. To avoid this, prune sparingly and carefully, and always use sharp and clean pruning tools.
Propagation of Acacia welwitschii Oliv. subsp. welwitschii
Acacia welwitschii Oliv. subsp. welwitschii, commonly referred to as Welwitsch's Acacia, is propagated via seeds, cuttings, and air layering.
Propagation by Seeds
The plant is best propagated via seeds. The best method is to sow the seeds in spring or early summer. Soak the seeds in water for 24 hours before sowing them. Sow in well-draining soil in a sterile pot. Cover the pot with a lid or plastic wrap. Keep the soil moist and warm and place it in a warm location. Germination is typically observed within 4 to 6 weeks. Once the seedlings have reached a sufficient size, they can be transplanted into larger pots or directly in the ground.
Propagation by Cuttings
Cuttings can also be used to propagate Acacia welwitschii Oliv. subsp. welwitschii. The cuttings should be taken in spring or early summer from the previous year's growth. The cuttings should be approximately 15 cm long and should be taken from the softwood found at the base of the mature plants. The leaves on the lower half of the cutting should be removed, and the cutting should be dipped in rooting hormone. The cuttings can be planted in a pot filled with a well-draining soil mix and kept moist. Rooting should occur within four weeks. Once roots have been established, the cuttings can be transferred to larger pots or transplanted in the ground.
Propagation by Air Layering
Propagation by air layering is another method to propagate Acacia welwitschii Oliv. subsp. welwitschii. To air layer the plant, a stem is selected, and a ring of bark is removed at a point where it will be covered with moist sphagnum moss. The moss is wrapped around the stem and enclosed in plastic wrap for a month. Once the roots have formed, the stem can be cut and planted in a well-draining soil mix.
Disease Management for Acacia welwitschii Oliv. subsp. welwitschii
Acacia welwitschii Oliv. subsp. welwitschii is a sturdy plant that can resist many diseases, but some diseases can still affect it. Here are some common diseases that might affect the plant:
- Fusarium Wilt: This disease can be recognized by yellowing and wilting of leaves branch by branch. The cause of this disease is a fungus called Fusarium solani. It can be managed by removing the diseased part and preventing the soil from extra moisture.
- Anthracnose: It is a fungal disease that can cause damage to the leaves, stems, and flowers of Acacia welwitschii. The signs of this disease are sunken spots on the leaves that may have dark borders. This disease can be managed by removing the affected parts of the plants and using fungicides.
- Root Rot: This disease can be recognized by the yellowing and wilting of leaves. The root system of the plant turns black and mushy, leading to the death of the plant. This disease is caused by a fungus known as Phytophthora cinnamomi, which thrives in poorly drained and moist soil. Managing this disease involves taking preventive measures such as reducing water stress and using a well-drained soil mix.
Pest Management for Acacia welwitschii Oliv. subsp. welwitschii
There are several pests that can damage Acacia welwitschii, but the good news is that they can be managed. Some of the common pests that can affect the plant include:
- Aphids: These insects can damage the plant by feeding on the sap, causing leaf yellowing, stunting of growth, and deformation of leaves. This pest can be managed through physical removal of the pest or using insecticidal soap.
- Spider Mites: They are tiny mites that can cause discoloration, wilting, and eventual leaf drop. They feed on the plant sap and can cause webbing when they become more established. The plant can be managed by regularly rinsing it with water or using insecticidal sprays.
- Thrips: These pests are tiny and mostly found on flowers. They can cause stunted growth, leaf drop, and discoloration. They can be managed through physical removal of the pest and the application of insecticidal soap or oil.
