Acer palmatum, on its common name Japanese Maple or Smooth Japanese Maple, is a deciduous shrub or small tree, sometimes with multiple trunks joining close to the ground. They are spectacular trees suitable for most landscapes and are grown for their attractive leaf shapes and colors, that add color and interest in the garden throughout the year because some of them have one color in spring, another in summer, and another in fall, and some even have winter interest.
The leaves are 4-12 cm long and wide, palmately lobed with five, seven, or nine acutely pointed lobes. Hundreds of cultivars are available, with countless leaf type forms (shallowly to deeply lobed), sizes, colors (ranging from chartreuse through dark green or from red to dark purple, others are variegated with various patterns of white and pink), bark texture and color and growing habits (from globose, branching to the ground to upright, vase-shaped), but the red-leafed cultivars are the most popular, followed by cascading green shrubs with deeply dissected leaves. These trees are suitable for borders and ornamental paths. Many varieties of Japanese Maple are successfully grown in containers. They are also a popular choice for bonsai.
Japanese Maple grows best in moist, well draining soils that are high in organic matter. If you live in an area with hot dry sun, plant your Japanese Maples in partial shade to protect them from scorching. In colder areas, where summer temperatures are more moderate, you can place them in a place with full sun. Dwarf varieties can be easily grow in large containers with good drainage. Always make sure that you tree is well watered over dry periods. Fertilize in early spring and water thoroughly after feeding.
Plant Japanese Maples out in spring, after all dangers of frost has passed. Provide them support stakes to prop up young slender branches until they have developed and strengthened, because the weight of the new foliage may tend to cause the branch to droop to the ground. Japanese Maples can be easily transplanted, even larger specimens. These trees have tendency to leaf out very early in the season, which makes them susceptible to spring frosts. A late frost may result in a loss of the new foliage, but the tree generally survives without any damage.
Prune Japanese Maples in late autumn or winter, while they are in their dormant period, remove any dead or damaged branches. You may prune them over the growing season to control their size or create the shape which suits your landscape needs. They adapt well to pruning and are easily thinned and sculpted to accentuate their graceful shape.
It is possible to propagate these trees from seeds, but the seedlings are more likely to be different than the parent plant in coloration or growing structure. The seeds of Japanese Maple require stratification in order to germinate. Other methods of propagations are by cuttings, tissue culture, budding or grafting.
The most known varieties are: Acer palmatum 'Bloodgood' - deep burgundy leaves color, Acer palmatum 'Dissectum' - vibrant green leaves that turn yellow in autumn, Acer palmatum 'Dissectum Flavescens' - extremely deeply lobed leaves, yellow-green in color that become yellow-orange in autumn, Acer palmatum 'Ogon-sarasa' - bronze-green leaves, Acer palmatum 'Orange Dream' - yellow-orange leaves in spring that turn yellow-green in summer and yellow in autumn, Acer palmatum 'Orangeola' - yellow-green leaves, Acer palmatum 'Ornatum' - deeply dissected and divided leaves, purple in spring, dark green in summer and golden yellow in autumn, Acer palmatum 'Tsumagaki' - golden-yellow leaves with red margins.
