Overview of the Zelkova Spach Plant
The Zelkova Spach, also known as the Japanese zelkova or keyaki tree, is a deciduous tree that belongs to the Elm Family. This plant is considered a medium-sized tree that grows slowly and has a lifespan of up to a hundred years. Zelkova Spach is a common tree species in Japan, Taiwan, and Korea, and it has been introduced to various parts of the world, including North America.
General Appearance
Japanese zelkova trees have a vase shape with a wide, spreading canopy that can reach up to 70 feet in width and height. The bark of mature trees is smooth, gray, and with an exfoliating texture, revealing an interesting pattern of orange-brown underneath. Its dark green leaves are serrated, oval-shaped, and alternate along the branches, usually turning a golden-yellow in fall, creating a striking autumn display.
Common Names
The Japanese Zelkova has several common names, including Keaki, Japenese grey bark Elm, and Sawleaf Zelkova. In China, it is known as "shan zhu yu", which means "mountain waxberry" referring to the resemblance of its fruit to the berries of the Myrica rubra tree.
Uses
Zelkova Spach is a popular ornamental tree, and its attractive features have made it an outstanding choice for landscapes, urban environments, and parks. Its large, spreading canopy offers shade in summer, while its colorful autumn foliage brings visual interest to any garden space. Beyond landscaping purposes, it's wood is hard, strong, and resilient, making it suitable for woodworks such as making furniture, flooring, and construction. Its leaves and bark have been used in traditional Chinese medicine to relieve fever, allergy symptoms and pain.
Light Requirements
Zelkova Spach thrives in bright and partially shaded areas. It can tolerate full sun exposure, but prolonged exposure may result in leaf scorch, especially during hot summer months. However, in areas with mild summers, full sun exposure can enhance growth and foliage appearance.
Temperature Requirements
Zelkova Spach is a hardy plant that can tolerate a wide range of temperatures. It can withstand extreme cold temperatures of up to -35°C during winter dormancy. However, during the growing season, it prefers moderate temperatures between 18-24°C.
Soil Requirements
Zelkova Spach thrives in well-drained soils that are slightly acidic to neutral with a pH range of 5.5-7.5. Compacted, waterlogged, or heavy soils hamper growth and are not suitable for the plant. The plant prefers loamy soils that offer a good balance of water retention and drainage.
Cultivation of Zelkova Spach
Zelkova Spach is a deciduous tree that is native to Japan, China, and Korea. It prefers to grow in areas with full to partial sun exposure in well-draining soil. The plant grows up to 80 feet in height and 60 feet in width, making it an excellent tree for urban landscapes and parks. To cultivate Zelkova, the first step is to choose a suitable location for planting.
Plant the tree in a hole that is twice as wide and deep as the root ball. The soil should be amended with organic matter to improve drainage and nutrient availability. It is essential to plant the tree at the same level it was in the container to prevent the roots from drying out and to promote healthy growth. Water the tree immediately after planting and every other day for the first two weeks.
Watering Needs
Zelkova Spach prefers to grow in moist, well-drained soil. Once established, the plant can tolerate some drought but may require additional watering during prolonged dry periods. Water the tree once a week during the growing season, providing enough water to saturate the root zone. Avoid watering the foliage to prevent waterlogging and fungal diseases.
Fertilization
Zelkova Spach does not require much fertilizer, but it benefits from occasional applications of slow-release fertilizer in the spring. Use a balanced fertilizer, such as 10-10-10, and apply it according to the package instructions. Avoid fertilizing the tree in the fall, as it may stimulate new growth that can be damaged by freezing temperatures.
Pruning
Zelkova Spach requires minimal pruning, as it forms a very attractive shape on its own. However, removing dead or diseased branches and thinning out the center of the tree promotes strong growth and improves air circulation. Prune the tree in late winter or early spring before new growth begins. Avoid pruning during the summer, as this may stimulate new growth that can be damaged by frost.
Propagation of Zelkova Spach
Zelkova Spach is a deciduous tree species that belongs to the family Ulmaceae. This tree is commonly propagated through various methods, which include seed propagation, vegetative propagation, and grafting.
Propagation by Seed
Propagation by seed is the easiest and most common method of propagating Zelkova Spach. Collect mature, viable seeds and remove from their fruiting structures. Allow the seeds to dry and then sow them in a seed bed or tray using well-draining soil. Water the soil regularly, but avoid overwatering to prevent the seeds from rotting. The seeds usually germinate within three weeks. Transplant the seedlings to larger pots or directly into the ground after they have developed a few leaves.
Propagation by Vegetative Cuttings
Propagation by vegetative cuttings works well for Zelkova Spach. Collect hardwood cuttings in early autumn before the onset of frost, when the wood of the tree has matured. Cut the branches into sections of about 20 cm in length, and remove all the leaves except for one at the top. Remove the bottom leaves and dip the cuttings into rooting hormone. Plant the cuttings in well-draining soil and keep them moist. Cover the pot or tray with a plastic bag or put it in a propagator to maintain the humidity levels. The cuttings should root within two to three months.
Propagation by Grafting
Propagation by grafting is a more complicated propagation method for Zelkova Spach but can be used to propagate cultivars or hybrids. Grafting involves attaching a branch or bud, called a scion, from the desired tree cultivar onto the rootstock of another tree. Select a compatible rootstock that is healthy and vigorous. Then gather scion from a healthy tree of the desired cultivar and attach it to the rootstock using grafting tape or wax. Keep the graft moist and warm. After several months, the graft should have fully bonded, and the plant is ready for transplanting.
Pest and Disease Management for Zelkova Spach
Zelkova Spach is a relatively hardy tree, but it is still susceptible to various diseases and pests that can harm its growth and appearance. Being aware of the common pests and diseases that can negatively affect the tree is crucial for its proper management.
Common Pests
There are several pests that commonly affect Zelkova Spach, including:
- Zelkova scale: This insect pest feeds on the tree's sap, causing yellowing and leaf drop. You can manage it by pruning affected parts and applying horticultural oils or insecticidal soaps.
- Japanese beetle: This beetle feeds on the tree's foliage, causing skeletonization of leaves. Handpicking the beetles and applying insecticides can help manage the problem.
- Spider mites: These mites feed on the tree's sap, causing yellowing and loss of foliage. Regularly hosing down the tree with water can help manage the pest.
Common Diseases
Zelkova Spach can also be affected by several diseases, including:
- Leaf spot: This fungal disease causes yellow or brown spots on the leaves. You can manage it by improving the tree's air circulation and applying fungicides.
- Anthracnose: This fungal disease causes brown spots and blotches on the leaves and twigs. You can manage it by pruning affected parts, improving the tree's air circulation, and applying fungicides.
- Canker: This fungal disease causes sunken, dead areas on the tree's bark and can lead to dieback. You can manage it by pruning affected parts and applying fungicides.
Regularly inspecting the Zelkova Spach for signs of pests and diseases and taking necessary measures to manage them is crucial for the long-term health and appearance of the tree.
