Red Japanese maple trees are a common decorative choice in many gardens. This medium-sized ornamental tree is well known for its foliage. The standard colour for the maple leaf is green in the summer and red in the autumn, but many varieties have been developed with leaf colours ranging from pink to burnt orange. The attractive appearance of this tree will suffer if leaves are shrivelling on the branches.
The red Japanese maple is sensitive to drought. When not receiving adequate water, the tree's leaves will eventually wilt, brown and then shrivel and drop. Prevent this problem by irrigating or otherwise watering your Japanese maple in times of water restriction. The leaves of the Japanese maple are delicate and can often be shrivelled merely from too much sun combined with windy conditions. This condition is known as leaf scorch. Plant your red Japanese maples in an area where they will receive some windbreak protection.
Fungal infections can cause the maple leaves to yellow, then shrivel up and defoliate. Examples include armicillia and verticillium. These fungi are found in the soil and attack the root system. A third fungus, anthranose, will damage the leaves and show similar symptoms to leaf scorch. Bacterial scorch causes a red-brown stain that is clearly visible on the otherwise healthy green leaf.
Treatment of diseases
Bacterial scorch cannot be cured, but can be slowed if caught early. Extra-attentive care and judicious pruning will be the most effective strategy. Apply fungicide to treat an ongoing fungal issue in your red Japanese maples. Soil-applied fungicides that the tree can absorb are best for larger trees. Sprays work well for smaller Japanese maples, but if the tree is very large, spraying is impractical. If the prognosis for your red Japanese maple is poor and there is concern that the tree will spread the disease to other trees, it may be best to remove it.
Prevention of diseases
Consider buying disease-resistant red Japanese maple saplings. Eliminate trees or individual branches that are heavily infected to keep the Japanese maple from being a vector for disease for your surrounding plants. Do not overwater and use a well-draining soil, adding sand if necessary. Keep pruning to the bare minimum necessary for tree health, and sterilise your shears often. Control pests well because they can spread disease between infected and healthy maple trees.