Origin
Olea enervis Harv. ex C.H.Wright is a species of plant that belongs to the family Oleaceae. It is commonly known as the Wild Olive or the Desert Olive, and it is native to southern Africa, specifically in the arid regions of Namibia and South Africa.
Common Names
The Wild Olive or the Desert Olive are the two most common names for Olea enervis. It is also sometimes referred to as the "Doringolienhout" in Afrikaans, which means "thorn olive wood".
General Appearance
Olea enervis is a small, slow-growing shrub or tree that typically reaches a height of 3 to 5 meters. It has a twisted trunk and thin, spiky branches covered in dense, grey-green leaves. The leaves are small and oval-shaped, measuring about 1 to 2 centimeters in length. The plant is dioecious, meaning that it has separate male and female plants with inconspicuous, small, whitish flowers.
The fruit of the Wild Olive is a small, round, fleshy drupe that is green when unripe and black when mature. The fruit contains a single, hard seed that is rich in oil, which is highly valued for its use in cosmetics, soaps, and traditional medicine.
Uses
Throughout southern Africa, various parts of the Wild Olive are used for medicinal purposes, such as treating hypertension, infections, fevers, and wounds. The oil extracted from the seeds is also used to make soaps and cosmetics, and the wood is prized for its durability and resistance to decay, making it ideal for making tools, furniture, and fencing.
Light Requirements
Olea enervis Harv. ex C.H.Wright prefers full sun to partial shade for optimum growth. It can tolerate some shade but will not thrive in deep shade. It is essential to ensure that the plant receives adequate direct sunlight for at least four to six hours daily.
Temperature Requirements
The plant is native to Africa and prefers a warm, temperate climate. It can tolerate a wide range of temperatures, from 10°C to 38°C, though it thrives in temperatures between 20°C and 30°C. The plant is frost and drought-resistant and can tolerate some heat stress.
Soil Requirements
Olea enervis Harv. ex C.H.Wright grows best in well-drained soils with a neutral to slightly acidic pH level. The plant can tolerate a wide range of soil textures, from sandy soil to clay loams, as long as it is well-draining. It requires soil that is rich in organic matter to provide adequate nutrients to support its growth.
Cultivation
Olea enervis Harv. ex C.H.Wright, commonly known as the Wild Olive, is native to South Africa and is a drought-tolerant plant. It is mostly found in dry scrubland, rocky hills, and mountain slopes. When grown indoors, the plant thrives in well-draining soil that contains organic matter.
The plant requires bright but indirect sunlight. In regions with hot summers, the plant should be given partial shade during the hottest times of the day.
Watering Needs
The Wild Olive is a drought-resistant plant and does not require frequent watering. It is best to wait until the soil has completely dried before watering. The frequency of watering will depend on the humidity, temperature, and amount of light the plant receives. As a general rule, the plant should be watered sparingly during the winter months and more frequently in the summer months.
Fertilization
The Wild Olive requires minimal fertilization. During the growing season, which is typically the spring and summer months, you can use a slow-release fertilizer. Alternatively, you can use a liquid fertilizer at 1/4 strength every two weeks. Do not fertilize the plant during the winter months when the plant is in a rest period.
Pruning
Pruning helps to promote growth and maintains the plant's shape. The Wild Olive can be pruned at any time of the year but is best done in the spring before new growth appears. When pruning, use sharp and clean pruning shears to avoid making ragged cuts that may damage the plant.
Remove any dead, diseased, or damaged branches. Cut back any excess growth that is taking away from the overall form of the plant. Trim the plant to maintain its desired size and shape.
Cut back approximately 1/3 of the previous year's growth. Failure to prune the Wild Olive plant may lead to an unattractive and scraggly appearance.
Propagation of Olea enervis Harv. ex C.H.Wright
Olea enervis Harv. ex C.H.Wright, commonly known as the Wild Olive, is propagated both sexually and asexually.
Sexual propagation
Olea enervis can be propagated by seed, although this method is less commonly used due to the variable quality of the resulting plants and slow growth. The seeds are harvested from mature fruits that have fallen naturally from the tree. They should be cleaned and planted in well-draining soil, kept moist, and in a warm location until germination.
Asexual propagation
Olea enervis can also be propagated asexually, either by rooting cuttings or layering.
Hardwood cuttings should be taken from mature, dormant wood in winter. They are then treated with rooting hormone and placed in a well-draining, sterile potting mix until they form roots. This method produces plants that are genetically identical to the parent plant.
Layering is another asexual propagation method, where a low-growing branch is stimulated to root while still attached to the parent plant by creating a wound and applying rooting hormone and moisture. Once roots have formed, the branch can be severed and potted up.
Disease Management
Olea enervis Harv. ex C.H.Wright is susceptible to several diseases that could affect its growth and yield if left unchecked. Some common diseases that affect the plant include fungal leaf spot, anthracnose, and bacterial blight.
One of the ways to manage fungal leaf spot is by practicing good sanitation. This involves picking up and disposing of fallen leaves and pruning infected plant parts. Fungicides could also be applied to manage the disease.
To manage anthracnose, a foliar fungicide could be used. Removing and destroying infected plant parts could also help prevent the spread of the disease.
For bacterial blight, pruning infected branches and using a copper-based bactericide could help control the disease.
Pest Management
Insects and mites could also attack Olea enervis Harv. ex C.H.Wright, leading to decreased yields and stunted growth. Some common pests that affect the plant include the olive fruit fly and spider mites.
For the olive fruit fly, cultural practices like harvesting fruit early or using pheromone traps could reduce infestation. Insecticides could also be used to manage the pest.
Spider mites could be managed by periodic irrigation to reduce plant stress, introducing natural predators like ladybugs or predatory mites, and using insecticidal soaps.
Regular scouting could help detect pests and diseases early, enabling timely management and preventing widespread damage to the plant.
