Japanese Acer

There are two main forms of Japanese Acer: A. japonica and A. Palmatum. Native to east Asia, these plants form a large bush or small tree with soft green, yellow or red lobed leaves.

Family: Sapindaceae (soapberry family)
Botanical Names: Acer palmatum and Acer japonicum
Common Names: Japanese Maple, Moon Maple

Foliage: Deciduous, paired, deeply-lobed leaves. Leaf colour can be green, yellow or red, depending on variety. Most varieties provide excellent autumn leaf colour.

Blossom: Small flowers, often followed by small winged fruits.

Flowering Period: Spring.

Soil: Moist but well-drained soil (sand or loam). Acid or neutral pH. Some varieties will tolerate chalky soil.

Conditions: Sun or partial shade. Planting aspect depends on variety, but most enjoy a shady, sheltered location.

Habit: Bushy.

Type: Large shrub or small tree.

Origin: Japan and East Asia

Hardiness: Hardy in the UK.

Planting and Growing Japanese Acers

Japanese maples do best in shelter and shade and prefer an acid soil. Many A. palmatum varieties are suitable for growing in large containers. When using containers it is best to use a general-purpose compost with added John Innes, rather than heavy loam-based types.

Taking Care of Japanese Acers

Hot dry air, cold wind and late frost can cause leaf scorch (browning at the edges). To avoid this plant in a position that is not affected by cold winds and in an area that does not get morning sun following a frosty night.

Acers cope with partial shade but the foliage colours up best in sunshine.

Water well, especially when grown in containers. Mulch in autumn to protect the shallow roots.

Pruning Japanese Acers

Acers can be pruned very lightly in late autumn and winter, when the trees are dormant. Remove any dead or crossing branches and prune to maintain an attractive shape and structure.

Pests and Diseases

Can be affected by Acer gall mite, aphids, caterpillars and horse chestnut scale. Prone to Verticillium wilt, Acer leaf scorch and honey fungus.

Propagating Japanese Acers

Increase from semi-hardwood cuttings, grafting or by layering.

Varieties of Japanese Acer

There are a great many varieties, usually with pale green, crimson or bronze finely-lobed leaves. Average height 10-20ft, spread 15-25ft.

For other maple species see Acers.

Acer palmatum is a deciduous small maple that is relatively slow growing and shade tolerant. Native to damp, shady forests of Asia, this species is highly variable and has been cultivated by Japanese gardeners for hundreds of years. Over 1000 varieties are available, including:

'Atropurpureum' one of the most attractive and popular varieties. Forms a slow-growing, rounded tree with dissected bronze-red foliage. Height to 18ft (4.5m).
'Beni-kawa' is an elegant, upright form with coral stems and green foliage that turns orange-yellow in autumn. Red flowers in spring. Height to 10ft (3m), spread 6ft (1.8m).
'Dissectum' forms a low rounded bush of slow growth. It has finely divided leaves, consisting of five to eleven pointed lobes, fresh green in colour becoming bronzy-yellow in the autumn. Height to 4ft (1.2m).
'Dissectum Ever Red' is a dwarf, weeping form with deeply dissected leaves that have burgundy tints from spring. Red-bronze autumn colour. Height to 3ft (90cm), spread 4ft (1.2m).
'Dissectum Garnet' has deep crimson finely divided leaves. Vigorous growth. Height to 4.5ft (1.3m).
'Filigree' has pale green, cream-mottled leaves that turn golden in autumn.
'Garnet' has leaves that are very finely fingered and deep crimson in colour.
'Kinshi' bears light green leaves with narrow, finger-like lobes. Slightly weeping habit. Orange autumn tints. Height to 13ft (4m).
'Orange Dream' is a bushy, spreading shrub with fresh green leaves that are orange tinted in spring and again in autumn. Red flowers in spring. Height to 10ft (3m).
'Osakazuki' is a popular variety, which produces large lobed leaves that turn an intense red in autumn. Height to 13ft (4m).
'Sango-kaku' has pink and yellow leaves in spring, turning green in summer and yellow again in winter. Orange and red stems. Red flowers in spring.
'Winter Flame' is a compact variety with coral-red shoots. The young foliage is pink-tinged, turning fresh green, then to red and gold in autumn. Height to 10ft (3m), spread 6ft (1.8m).

Acer japonicum (full moon maple) is a bushy, slow growing species with lobed, palmate, green leaves that turn rich crimson in autumn. It prefers a moist, semi-shaded, sheltered position. Varieties include:

'Aconitifolium' a free-flowering, multi-stemmed rounded tree with deeply-lobed deep green leaves that turn an intense scarlet in autumn. Height to 16ft (5m), spread 20ft (6m).
'Aureum' is a compact form with golden yellow lobed leaves. Makes a delightful rounded, slow-growing, bush. Height to 4ft (1.2m).
'Vitifolium' forms a small deciduous tree with deeply cut leaves. Dramatic autumn colour. Height and spread to 13ft (4m).