The dwarf Japanese maple (Acer palmatum) is a smaller, slower-growing cousin of the upright Japanese maple (Acer japonicum). Dwarf Japanese maples are also known as Threadleaf or Cutleaf Japanese maples because of their feathery, fine-toothed leaves. These varieties only grow between 8 and 12 feet tall. They make excellent specimen trees, as focal points in the landscape, and some are small enough to be grown in containers on a patio or deck. The brilliance of their leaves makes for a stunning autumnal show.
Because of their weeping habit and lush colors, dwarf Japanese maples make an eye-catching statement in the garden. The leaves are long and slender, and separated into feathery pointed lobes. Colors vary among cultivars, but may be gold, pale green, deep red or burgundy. In the autumn, this tree puts on a spectacular show-red leaves turn a more brilliant red, green-leafed varieties turn gold, and gold types turn orange or yellow. Branches can be deep purple, red or green. These trees form a mounding, cascading sweep of branches and can have a spread up to 20 feet wide, depending on the cultivar.
Where to Plant
Dwarf Japanese maples are hardy in zones 5 to 8 and they prefer full sun to part shade. Those varieties with red leaves require full sun. Afternoon shade, especially in southern regions, is ideal. These maples require fertile, well-drained, moist, slightly acidic soil. They will tolerate a number of soil conditions, as long as it is moist. They should be protected from strong winds.
How to Plant
Plant container-grown trees in the fall, before the ground freezes. Spring is acceptable, but young trees may suffer in the summer heat. Dig a hole twice the diameter of the root ball. Add compost, peat moss or manure to the soil and mix well. Place the tree into the hole and make sure it's level. Backfill with soil and a bit of water as you go, to alleviate any air pockets. Compact the earth and give the tree a good soaking. Place a 3-inch layer of mulch around the base of the tree (leave an inch or two clear of the trunk for air circulation), which will help to keep in the moisture.
Japanese maples require regular watering during their first couple of years. Deep watering twice weekly is recommended. Periods of excessive heat or drought will require further watering. Make sure the mulch underneath the tree is always available. Decrease the amount of water during the fall, which will encourage more dramatic colors in the changing leaves. Mulch heavily in the late fall and, during the winter, if your tree has accumulated snow, remove it carefully so as not to break any branches.
Dwarf Japanese maples require little or no annual pruning except to remove any dead or broken branches. In late summer and early fall you can prune for shape. If your tree has become overgrown in the center, you may want to cut out branches to let in more air. These little trees can also be shaped however you wish. Thinning the stems so that a single trunk remains is a popular pruning method, which adds a graceful appearance to this magnificent little tree.