Acer pictum aka The Painted Maple

Acer pictum, or painted maple, is a deciduous tree. It belongs to the soapberry family, Sapindaceae. Its native range spans much of eastern Asia. Oregon State lists Tibet, China, southeastern Siberia, Korea, and Japan. Kew records a narrower native range of Japan. Some sources use the older name Acer mono. This maple is distinct from castor aralia, despite past name confusion.

Garden height varies between sources. RHS gives 26–39 feet [8–12 metres] for mature trees. Oregon State gives 40–60 feet [12–18 metres], with extremes reaching 90 feet [27 metres]. RHS lists a spread of 13–26 feet [4–8 metres]. The crown spreads and takes on a rounded shape. Young bark is smooth and gray. Shallow cracks form along the trunk as it ages. Twigs can be green, olive-brown, or reddish-brown. They may lack hairs or carry a few.

The leaves grow in pairs along the stems. Each simple leaf has five to seven pointed lobes. The base has a slight heart shape. Leaf edges are mostly smooth, though some have large teeth. Upper surfaces are green; the undersides are paler. Brown hairs may grow along the main veins below. The slender leaf stalk releases milky sap when cut. Fall leaves turn yellow or gold, sometimes with red-purple tones. Green-yellow flowers open with the new leaves in spring. Missouri Botanical Garden gives April to May as bloom time. The small flowers offer little visual impact. Paired winged fruits, called samaras, follow the flowers. Their wings spread at angles that vary between trees.

Grow painted maple in sun or partial shade. It needs fertile soil that stays moist but drains well. RHS accepts clay, loam, and sand across a broad pH range. Missouri Botanical Garden lists medium water needs and low maintenance. It gives USDA zones 5–8; Oregon State also mentions zone 4. RHS rates the tree H6 for UK conditions. Full size may take 20–50 years. RHS places pruning between late autumn and midwinter. Growers can use seeds, softwood cuttings, layering, or grafting.

Painted maple serves as a specimen or accent tree. Its rounded crown and fall leaves provide landscape interest. Serious pest and disease trouble is not usual. Still, aphids, scale, borers, caterpillars, and mites may occur. Possible diseases include Verticillium wilt, leaf spots, and root rots. RHS also lists leaf scorch and honey fungus. The supplied species sources do not establish edibility or toxicity.