Origin
Olea welwitschii (Knobl.) Gilg & Schellenb. is a plant species belonging to the family Oleaceae. It is commonly found in southern Africa, specifically in Angola and Namibia.
Common Names
This plant is known by several common names, including Desert Olive, Geduldbos, and Welwitschia Wild Olive.
Uses
The Desert Olive plant has several uses. The leaves and bark of the plant are used traditionally by some indigenous communities for medicinal purposes. The fruits of the plant are edible and are used for making jams and preserves. The tree’s wood is dense and durable, making it a valuable source of timber for furniture and other household items.
General Appearance
The Desert Olive plant is a small, slow-growing tree that typically reaches a height of 2-4 meters. It has a bushy appearance with a rounded crown and drooping branches. The leaves of the plant are narrow and elongated, with a dark green color on top and a paler color underneath. The trunk is thick and can have a gnarled appearance, making the tree look older than it actually is. The bark of the Desert Olive is dark and rough, with deep, vertical cracks. The tree produces small, cream-colored flowers that are followed by round, green fruit that turns black when ripe.
Growth Conditions of Olea welwitschii (Knobl.) Gilg & Schellenb.
Olea welwitschii is a small tree that is native to tropical Africa. It can grow up to 10 meters in height and has a bushy growth habit. The tree is known for its attractive white flowers and edible fruits.
Light Requirements
Olea welwitschii requires full to partial sunlight to thrive. The tree grows best in areas with bright, direct sunlight, but it can also tolerate some shade. In areas with too much shade, the tree may grow slower and produce fewer flowers and fruits.
Temperature Requirements
Olea welwitschii is a tropical plant and requires warm temperatures to grow. The tree can tolerate a temperature range of 20°C to 30°C and cannot withstand freezing temperatures. In areas with colder climates, the tree may not survive the winter.
Soil Requirements
Olea welwitschii prefers well-drained soils that are rich in organic matter. The tree can grow in a variety of soil types, including sandy, loamy, and clay soils. However, it cannot tolerate waterlogged soils or soils with high levels of salinity.
The optimal pH range for Olea welwitschii is between 6.0 and 7.5. If the soil pH is too low or too high, the tree may not grow well and may even die.
Water Requirements
Olea welwitschii requires regular watering to grow and produce fruits. The tree prefers moist soils but cannot tolerate waterlogged conditions. It is important to ensure that the tree does not dry out completely between watering sessions. During the dry season, the tree may require additional watering to prevent wilting.
In conclusion, Olea welwitschii requires full to partial sunlight, warm temperatures, well-drained soils that are rich in organic matter, and regular watering. By providing these growth conditions, the tree can thrive and produce attractive flowers and edible fruits.
Cultivation Methods for Olea welwitschii (Knobl.) Gilg & Schellenb.
Olea welwitschii (Knobl.) Gilg & Schellenb. is a hardy plant that can grow in various soil types. It prefers well-drained soils with neutral to slightly alkaline pH. The plant grows well in full sun and requires a warm climate with temperatures above 20°C. It is tolerant of drought and can survive in areas with low rainfall.
Watering Needs for Olea welwitschii (Knobl.) Gilg & Schellenb.
When establishing young plants, regular watering is needed until the plant becomes established. Once established, Olea welwitschii (Knobl.) Gilg & Schellenb. is a drought-tolerant plant that requires minimal watering. It is important to allow the soil to dry between watering, as over-watering can lead to root rot and other diseases.
Fertilization of Olea welwitschii (Knobl.) Gilg & Schellenb.
Olea welwitschii (Knobl.) Gilg & Schellenb. does not require much fertilization. However, a balanced fertilizer can be applied once a year during the spring. The fertilizer should be spread around the base of the plant, and care should be taken not to allow the fertilizer to touch the trunk or foliage.
Pruning Olea welwitschii (Knobl.) Gilg & Schellenb.
Pruning is not typically necessary for Olea welwitschii (Knobl.) Gilg & Schellenb. However, if pruning is desired, it should be done during the dormant season in winter. Pruning can be done to control the size and shape of the plant or to remove any dead or damaged branches. Care should be taken not to remove more than one-third of the plant during pruning to avoid stressing the plant.
Propagation of Olea welwitschii (Knobl.) Gilg & Schellenb.
Olea welwitschii (Knobl.) Gilg & Schellenb. can be propagated by seeds, cuttings, and air-layering.
Propagation by Seeds
Seeds of Olea welwitschii (Knobl.) Gilg & Schellenb. can be sown directly into the soil or in pots filled with well-draining soil. The seeds should be covered lightly with soil and kept at a temperature of 25-30°C. Germination usually occurs within 4-6 weeks.
Propagation by Cuttings
Propagation by cuttings is an easy and fast way to propagate Olea welwitschii (Knobl.) Gilg & Schellenb. Semi-hardwood cuttings should be taken during the summer months and treated with rooting hormone before being planted into well-draining soil. The cuttings should be kept in a warm and humid environment until they develop roots.
Propagation by Air-layering
Air-layering is another method of propagating Olea welwitschii (Knobl.) Gilg & Schellenb. In this method, a section of the stem is wounded and wrapped with moist sphagnum moss and covered with plastic. Roots will form at the wounded section and can then be planted into well-draining soil once they develop.
Disease Management for Olea welwitschii
Olea welwitschii is a hardy plant, but it is still susceptible to a few diseases. The most common disease affecting this plant is leaf spot. The spots may be brown or black on older leaves and will cause leaf wilting or even defoliation if left untreated. A fungicide containing copper can be used to manage leaf spot disease. Apply the fungicide according to the manufacturer's instructions, making sure to cover all parts of the plant.
Another disease that may affect Olea welwitschii is verticillium wilt. Symptoms may include yellowing and wilting of the leaves, which will eventually die. This disease is caused by soil-borne fungi and there is no cure for it. The best management strategy is to remove and destroy all infected plants and avoid planting Olea welwitschii in the same soil for several years, to prevent the spread of the fungi.
Pest Management for Olea welwitschii
Olea welwitschii is relatively pest-resistant. However, a few pests that can affect this plant include aphids, spider mites, and scale insects. Aphids are small, crawling insects that can damage the leaves and suck the sap from the plant, causing it to weaken. A strong jet of water can be used to knock the aphids off the plant. Insecticidal soap can also be used to control aphids.
Spider mites are tiny insects that suck the sap from the leaves of the plant, causing yellowing and browning of leaves. They spin webs on the leaves and can quickly infest the plant. A miticide can be used to control spider mites. It is important to follow the instructions carefully and to repeat the treatment as necessary.
Scale insects are small, hard, shell-like insects that can attach themselves to the leaves and stems of the plant, sucking the sap from it. They secrete a sticky substance that can attract ants and cause the plant to become covered in black sooty mold. Applying horticultural oil to the plant can control scale insects. Make sure to cover all parts of the plant and to repeat the treatment as necessary.
