Shrubs, trees and climbers

Japanese maple

AcerSapindaceae
Also: Acer
AT A GLANCE
Part shade Water: average H6down to −20 °C 2–4 m tall · 2–4 m wide In a pot: yes

Japanese maples are bought for autumn colour and lost to wind. The fine-cut leaf that makes them beautiful is also thin enough to scorch brown at the edges in a dry east wind or an exposed sunny corner, and once scorched it stays that way until it falls.

So the whole of their care is a siting decision: shelter, dappled light, soil that never dries out, and a pot big enough that the root ball does not bake. Pruning barely comes into it — they bleed sap heavily if cut in spring, and most never need it.

Care

Light

Sheltered from strong wind and hot afternoon sun, which scorches the fine leaves, especially on purple-leaved cultivars.

Water

Dislikes both drought and waterlogging; consistent moisture is key.

Soil

Fertile, humus-rich, well-drained, slightly acidic to neutral soil; excellent in a large pot with peat-free, ericaceous-leaning compost.

Pruning

Minimal — remove only dead, damaged or crossing branches in late autumn/winter while dormant, to avoid heavy sap 'bleeding' that occurs if cut in spring.

Feeding

Very little: a mulch of leaf mould in spring, and a slow-release feed only for a container plant. Japanese maples are damaged far more by wind, drought and scorch than by poor feeding, and a nitrogen-rich feed gives soft growth that scorches worse.

Propagation

Named cultivars are grafted and will not come true from seed or root from ordinary cuttings — this is not realistically a home job. Green-leaved seedlings appearing under an established tree can be potted on, but they will not match the parent.

Month by month

Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.

  1. AprilWater consistently through spring and summer, especially in a pot. how ›
  2. MayShelter from late frosts and cold winds, which can scorch the emerging spring leaves. how ›
  3. NovemberRemove only dead, damaged or crossing branches while fully dormant. how ›

Months based on climate: UK. Your choice stays on this device.

  1. AprilWater consistently through spring and summer, especially in a pot. how ›
  2. NovemberRemove only dead, damaged or crossing branches while fully dormant. how ›

Months based on climate: Northern Italy. Your choice stays on this device.

  1. MarchWater consistently through spring and summer, especially in a pot. how ›
  2. NovemberRemove only dead, damaged or crossing branches while fully dormant. how ›

Months based on climate: Central Italy. Your choice stays on this device.

  1. MarchWater consistently through spring and summer, especially in a pot. how ›
  2. DecemberRemove only dead, damaged or crossing branches while fully dormant. how ›

Months based on climate: Southern Italy and islands. Your choice stays on this device.

Common problems

Leaf scorch

How to spot it. Crispy brown leaf edges from wind, hot sun or drought.

What to do. Move to a more sheltered spot, increase watering.

Verticillium wiltfull sheet ›

How to spot it. Sudden branch dieback.

What to do. Cut out affected wood promptly, avoid planting another Acer in the same spot.

How to spot it. On soft new growth.

What to do. Encourage predators.

Popular varieties

Acer ‘Bloodgood’AGM3–5 m × 3–4 m · April–MayApril–MayMarch–AprilMarch–April
Acer ‘Dissectum Atropurpureum’AGM1.5–2.5 m × 2–3 m · April–MayApril–MayMarch–AprilMarch–April
Acer ‘Katsura’AGM3–4 m × 2.5–3 m · April–MayApril–MayMarch–AprilMarch–April
Acer ‘Orange Dream’2.5–3.5 m × 2–3 m · April–MayApril–MayMarch–AprilMarch–April
Acer ‘Osakazuki’AGM4–6 m × 4–5 m · April–MayApril–MayMarch–AprilMarch–April
Acer ‘Sango-kaku’AGM4–6 m × 3–4 m · April–MayApril–MayMarch–AprilMarch–April

Questions

Japanese maple: is it hardy?

H6: Hardy in the vast majority of UK gardens. It survives down to −20 °C.

Can it grow in a pot?

One of the best small trees for a large, permanent pot, particularly compact cultivars.

Japanese maple: when do you prune it?

Minimal — remove only dead, damaged or crossing branches in late autumn/winter while dormant, to avoid heavy sap 'bleeding' that occurs if cut in spring. In the calendar for UK, pruning falls in November.

When do you feed it?

Very little: a mulch of leaf mould in spring, and a slow-release feed only for a container plant. Japanese maples are damaged far more by wind, drought and scorch than by poor feeding, and a nitrogen-rich feed gives soft growth that scorches worse. Feeding months, UK: April.