Acer palmatum var. dissectum 'Inaba-shidare'

Common Name: Japanese maple 
Type: Deciduous shrub
Family: Sapindaceae
Zone: 5 to 9
Height: 6.00 to 10.00 feet
Spread: 8.00 to 15.00 feet
Bloom Time: April
Bloom Description: Red
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Street Tree
Flower: Insignificant
Leaf: Colorful, Good Fall
Tolerate: Rabbit, Black Walnut

Culture

Best grown in moist, organically rich, slightly acidic, well-drained soils in full sun to part shade. Grows well in sandy loams. May be grown in full sun in the northern parts of its growing range, but prefers some part afternoon shade in the southern parts (including St. Louis) of its growing range. New foliage may scorch in full sun locations in hot summers areas, particularly if soils are not kept consistently moist. Mulch helps retain soil moisture and keep roots cool. Avoid hot and dry sites. Site in locations protected from strong winds. Pruning is best kept to a minimum, but if needed should be done in late fall to mid winter. Spring or summer pruning often results in significant bleeding.

Noteworthy Characteristics

Acer palmatum, commonly called Japanese Maple, is a deciduous shrub or small tree that typically grows to 10-25' (infrequently to 40') tall. It is native to Japan, Korea and China. General plant form is rounded to broad-rounded, often with low branching. Each palmate green leaf (2-5" long) has 5 to 7 but less frequently 9 toothed lobes. Small reddish-purple flowers in umbels bloom in spring (April) followed by winged samaras in pairs which ripen in September-October. Fall color includes an often spectacular combination of shades of yellow, red, purple and bronze.

Var. dissectum is typically a much smaller, rounded, slow-growing shrubby form (often with cascading branching) that rarely matures to more than 12' tall with a larger spread. Palmate leaves, each having 7-11 deeply incised lobes, are deeply cut to the base of the leaf. These dissected-leaf shrubs are commonly called laceleaf Japanese maple, cutleaf Japanese maple or threadleaf Japanese maple. Dissectum means deeply cut in reference to the deeply cut, feathery nature of the leaves.

Genus name is the Latin name for a maple tree.

Specific epithet is in reference to the palmate nature of the leaves. Each leaf has several lobes (typically 5–7) that all originate from one point looking like an open hand with outstretched fingers.

‘Inaba-shidare' is a dissected cultivar that typically grows in an upright, rounded but cascading form to 4-6' tall over the first ten years, eventually maturing to 10' tall and to 12' or more wide. It is noted for its lace-like foliage that emerges deep purple in spring, matures to purple-red by summer and finally turns bright red in fall. Palmate, 7-lobed, purple-red leaves (to 6" long) are deeply cut and dissected. Small reddish flowers in spring are somewhat attractive on close inspection, but are not showy from a distance.

Problems

Potential disease problems include stem canker, leaf spots, fusarium, verticillium wilt, botrytis, anthracnose and root rots. Potential insect pests include aphids, scale, borers and root weevils. Mites may be troublesome. Foliage tends to leaf out early in spring and is subject to damage from late spring frosts. Chlorosis may occur in high pH soils.

Uses

Dissected forms of Japanese maples are generally grown for their attractive foliage and low-spreading shape. Specimen/accent or group around the home or yard or patio or periphery of the border or rock garden. Good sun-dappled understory plant. Dissected foliage and cascading form can be showcased by planting his cultivar near a pond or water garden. Smaller plants can be effective in containers.