Acer palmatum, also called Japanese maple, grows 8 to 25 feet tall, depending on the cultivar. It is hardy in USDA zones 5 to 8 (see Resources for map); it is susceptible to both freezing and sun scorch in areas beyond those zones. The Japanese maple is a slow-growing tree prone to diseases such as verticillium wilt and stem cankers. Knowing how to create the right environment for the plant and care for it properly, however, will go a long way in producing a healthy tree.
Plant the tree in a protected area – next to a building, for example – with part shade, part sun or full shade. This will protect it from sun scorch on the leaves and injury from drying winds. The Acer palmatum likes acidic or slightly alkaline well-drained soil. At the time of planting, mix organic compost into the soil to increase the nutrients available for the tree.
Place a layer of 2 to 4 inches of mulch around the tree, keeping it 6 inches away from the trunk. This will increase the moisture content of the soil and keep down weeds. The tree responds well to this, as it is not very drought tolerant.
Water the tree regularly, keeping it moist until it starts to grow on its own. Decrease the watering frequency after the tree takes root, allowing the soil to dry slightly in between. Take care to keep the tree moist in the hot, dry summer months, especially in the first two to three years.
Fertilize with a slow-release tree and shrub food just as new growth emerges in the spring. Follow the directions on the package for application instructions, but fertilize lightly. This tree needs little food to grow well.
Prune in late fall or winter while the Acer palmatum is dormant. Cut off any dead, diseased, broken or out-of-place branches with pruning shears. Do not shape or shear, as the value of the tree lies in its natural look.