The Elaeagnus umbellata Thunb.
The Elaeagnus umbellata Thunb., commonly known as the autumn olive or the Japanese silverberry, is a deciduous shrub in the family Elaeagnaceae. It is native to East Asia, including China, Korea, and Japan, but has been introduced to other regions of the world, particularly in North America.
Appearance
The plant grows up to 3-5 meters in height and has a spreading habit. It has grayish-brown, scaly bark and elliptical to lanceolate leaves that are 4-10 centimeters long and 2-4 centimeters wide. The leaves are dark green on the upper surface and silvery or brownish on the underside, with small scales that give them a metallic appearance. The plant produces small, fragrant yellow to creamy-white flowers in axillary clusters in late spring, followed by edible red or pinkish-red berries that ripen in the fall.
Uses
The autumn olive has several uses. The plant is grown as an ornamental shrub in gardens and parks because of its attractive foliage and showy fruits. The plant is also used for erosion control due to its ability to grow in poor soils and its nitrogen-fixing properties. The berries of the autumn olive are edible and can be used to make jams, jellies, and sauces. The plant has also been used in traditional medicine to treat various ailments, such as coughs, sore throats, and skin irritations.
However, the plant's aggressive growth and ability to form dense thickets can make it invasive and harmful to native plant communities. In some regions, it is considered a noxious weed and efforts have been made to control its spread.
Growth Conditions for Elaeagnus umbellata Thunb.
Elaeagnus umbellata Thunb., also known as autumn olive, is a woody shrub that is native to East Asia but widely grown in North America as an ornamental plant and as a source of edible fruit. This plant has a highly versatile growth habit and can thrive in a wide range of environmental conditions.
Light Requirements
Autumn olive is a highly adaptable plant in terms of light requirements. It can grow under full sun, partial shade, and even light to moderate shade. However, autumn olive produces the most fruit when it received adequate sunlight. In areas with hot summers, it may benefit from partial afternoon shade.
Temperature Requirements
Autumn olive is a cold-hardy plant that can tolerate temperatures as low as -40°F. However, it grows best in regions with long, warm summers and relatively mild winters, such as USDA hardiness zones 5 to 8. In low-temperature regions, the plant may suffer from cold damage or produce less fruit.
Soil Requirements
Autumn olive is a highly adaptable plant that can grow in a variety of soil types. However, it prefers well-drained, slightly acidic soils with a pH range of 5.5 to 7.0. It can tolerate moderately saline soils but struggles in waterlogged or poorly drained soils. In regions with nutrient-poor soils, autumn olive may benefit from regular fertilization.
Cultivation
Elaeagnus umbellata Thunb. commonly known as autumn olive or Japanese silverberry, is an easy-to-grow shrub that can be cultivated in diverse soils, although it prefers well-drained soils with a slightly acidic to neutral pH. It is an incredibly hardy plant that can tolerate harsh environmental conditions like drought, heat, and frost and can be grown in USDA Hardiness Zones 3 to 8. It requires adequate sunlight and can grow in full sun to partial shade.
Watering Needs
Elaeagnus umbellata Thunb. is drought-tolerant, but it requires regular watering in the first year after planting to help it establish its roots. Once it is well established, the plant can survive with minimal watering, except in drought conditions. During dry spells, the plant needs deep watering to help it develop deep roots that can reach the underground water. Too much watering can cause root rot problems.
Fertilization
Fertilization is necessary for Elaeagnus umbellata Thunb. to thrive, especially in soil with poor nutrients. A balanced fertilizer, with equal amounts of nitrogen, phosphorus, and potassium, is suitable for the plant. Fertilization should be done in spring or early summer before the plant starts its growing season. It would be helpful to use organic fertilizers that gradually release nutrients to the soil and complement them with mulching to conserve soil moisture.
Pruning
Elaeagnus umbellata Thunb. requires minimal pruning; however, it benefits from pruning for shape and size control. Pruning should be done in late winter or early spring before the growing season starts. Cut down the oldest branches, those that are more than three years old, close to the ground level. Remove any dead, diseased, or damaged branches. You can also trim back the tips of the plant to encourage bushier growth. Ensure to use sterile and sharp pruning tools to avoid transmitting diseases.
Propagation methods of Elaeagnus umbellata Thunb.
Elaeagnus umbellata Thunb. can be propagated through various methods such as seeds, cuttings, layering, and suckers.
Propagation by seeds
Seeds of Elaeagnus umbellata Thunb. can be collected in autumn when the plant produces ripe fruit. The seeds can be sown either in autumn or spring after they have been stratified for 2-3 months in a refrigerator. The germination of seeds can be improved by soaking them in water for 24 hours before sowing.
Propagation by cuttings
Softwood stem cuttings of Elaeagnus umbellata Thunb. can be taken in early summer and hardwood cuttings can be taken in late autumn or winter. The cuttings should be about 15 cm long and should be dipped in rooting hormone before planting. Cuttings should be planted in well-draining medium and kept moist until rooting occurs.
Propagation by layering
Elaeagnus umbellata Thunb. can be propagated by layering where a branch is bent and buried into the soil so that the tip of the branch is exposed above the ground. The stem should be wounded at the point of contact with the soil to promote rooting. The buried portion of the stem should be kept moist and the new plant can be separated from the parent plant once it develops roots.
Propagation by suckers
Elaeagnus umbellata Thunb. is known to produce suckers or shoots from the roots. These suckers can be transplanted to a new location after they have developed roots. The new plant should be watered regularly until it establishes itself.
Disease Management
Elaeagnus umbellata Thunb. is generally a robust plant that can tolerate various environmental conditions. However, it can still be prone to certain diseases that can impact its growth and productivity. Here are some common diseases that may affect the plant and ways to manage them:
Crown gall
Crown gall is a bacterial disease caused by Agrobacterium tumefaciens that commonly affects the roots and crowns of Elaeagnus umbellata Thunb. plants. Symptoms of this disease include swollen, rough, and cracked stems or roots. To manage crown gall, it is best to remove and destroy any infected plants and avoid planting new vegetation in the same location.
Leaf spot
Leaf spot is a fungal disease that can cause small, dark spots on leaves and eventually cause leaves to yellow and fall off. To prevent this disease, water plants at the base, avoid getting the foliage wet, and ensure good air circulation. If leaf spot does occur, remove and destroy any infected leaves and apply a fungicide.
Pest Management
Elaeagnus umbellata Thunb. can also be vulnerable to pests, which can cause significant damage to the plant. Here are some common pests that may affect the plant and ways to manage them:
Mites
Mites are tiny, spider-like creatures that can cause significant damage to Elaeagnus umbellata Thunb. by sucking sap from leaves and stems. To manage mites, spray the plant with a high-pressure water stream or pesticide. Ladybugs and lacewings may also be helpful in controlling mite populations.
Leafhoppers
Leafhoppers are small insects that can cause damage to Elaeagnus umbellata Thunb. by sucking sap from the leaves, causing them to turn yellow or brown. To manage leafhoppers, use insecticidal soap or neem oil. Pruning away heavily infested leaves can also help reduce the population of these insects.
Japanese beetles
Japanese beetles are a common pest that can cause significant damage to Elaeagnus umbellata Thunb. by feeding on leaves, flowers, and fruit. To manage Japanese beetles, the use of pesticides is recommended. Handpicking and removing the beetles is another effective method of control.
