Japanese maple, Acer palmatum
Scientific Name
Acer is Latin for “sharp” and may also be from the Celtic ac, which means “hard” in reference to the wood; palmatum means “hand-like” and refers to the shape of the leaves.
Common Name
Japanese maple refers to the tree’s native habitat of Japan.
NATIVE RANGE AND HABITAT
Japanese maple grows in Japan, central China and Korea. It has been long cultivated by the Japanese. The tree was introduced to England in 1820.
CONSERVATION INFORMATION
Not native to Kentucky.
DESCRIPTION
Growth Habit and Form
Japanese maple is a small deciduous tree or large shrub with a broadly spreading crown. The plant can be grown as a small single-stemmed tree or large multiple stemmed shrub. The habit is rounded to broad-rounded, with a layered branching structure similar to flowering dogwood. Trees typically grow 15 to 25 ft. tall with a spread equal to or greater than the height. There is great variation in this species due to the large number of cultivars in the trade.
Leaves
Leaves of the species form are oppositely arranged, hand-shaped, 2 to 5 inches long and have 5 or 7 lobes. Leaves emerge in early spring. Summer color is green and autumn color varies from orange to yellow to red to purple.
Flowers
The small, reddish flowers are borne in stalked, umbrella-shaped clusters. Flowers bloom between May and June and are insect pollinated.
Fruit
Fruit is a winged seed called a samara; they are green to red and ½ to ¾ inch long. Samaras ripen between September and October and are scattered by wind.
Bark
The bark is green to gray and smooth.
Wild and Cultivated Varieties
The cultivation and selective breeding of Japanese maple trees goes back over three centuries. There are some 300 cultivars to choose from. Characteristics such as leaf shape and color and growth form (i.e., upright growing type and dwarf type) have all been carefully selected to produce a vast range of cultivars. The cultivars vary greatly in their cultural requirements. Some of the best known cultivars are ‘Moonfire’, ‘Dissectum’, ‘Bloodgood’, and ‘Osakazuki’.
HORTICULTURE
Landscape Use
Japanese maple is a terrific garden plant. It is one of the most versatile small trees for use in the landscape. It exists in a multitude of forms that provide a wide range of sizes, shapes, and colors. Japanese maple is a magnificent specimen or accent plant and performs well in a grouping or in a shrub border.
Hardiness Zone
Depending on the cultivar, USDA zones from 5 to 8. The hardiness zone for the species form is zone 5.
Growth Rate
Young trees tend toward a medium growth rate, 10 to 15 feet over a 10 year period. Growth rate slows with age.
Cultivation and Propagation Information
Trees do best in moist, fertile, well-drained soils. Best growth is in light shade. Protect trees from harsh winds and late spring frost. Transplant balled and burlapped tree or as a container-grown plant into moist, high organic, well-drained soil. Plants can be propagated by seed and softwood cuttings.
Diseases and Insects
Japanese maple has very few insect or disease problems.
Wildlife Considerations
Maple trees provide homes, shelter and food for wildlife.
Maintenance Practices
Relatively trouble-free given appropriate cultural conditions.
TRADITIONAL AND MODERN USES
Leaves feel similar to paper and are used to make bouquets in Japan.
On the Chinese calendar, October is represented by Japanese maple leaves.
Japanese maple has long been cultivated in Japan and was introduced into cultivation in Europe in the early 1800s.