- Common names: maple
- Botanical name: Acer
- Family: Soapberry (Sapindaceae)
- Type: Shrubs and trees
- Main attribute: Autumn leaf colour
- Planting season: September to March
- Height: 2-12m (7-40ft)
- Spread: 2-8m (7-26ft)
- Aspect: Sun or semi-shade
- Hardiness: H6-H7
- Difficulty: Easy to average
Should you be stopped in your tracks by the blazing colour of a tree this autumn, it is likely to be a maple (Acer). Their distinctive palmate leaves burn breathtaking, vivid shades of scarlet, ruby, or gold before they fall, outshining most trees in the vicinity. Some acers also offer colourful spring foliage; others have a sculptural spreading shape with multiple trunks; and a few provide attractive bark during the winter months.
Of the 153 species, around 80% are classed as native to Asia, with the rest mostly native to North America, Europe, and North Africa. It is believed that the plants all originated in Asia and gradually spread – for example, via the Bering Land Bridge. In the modern era, of course, many were introduced. The most well-known garden form – the Japanese maple Acer palmatum – was brought to Europe by Swedish botanist Carl Peter Thunberg. He decided upon the species name palmatum because the leaves resemble a hand. The word Acer is thought to derive from the Latin acris (sharp), after the pointy tips of the leaves.
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While the foliage is the focus for most people, to a musician, the magic of a maple is its wood. Possessing the golden combination of strength and great resonance, it is the favoured tonewood used to carve the body back of a violin. The tiger stripes on the back of a Stradivarius are the grain of maple (probably A. platanoides). Some luthiers will even visit a maple before it is cut to check that the tree is growing in the optimum conditions to produce the right stiffness and tone.
The Romans used sturdy maple wood to fashion writing desks; and, in the US today, robust furniture and even bowling alleys are made from A. saccharum. Also known as the sugar maple, A. saccharum is grown in Canada for maple syrup, which is made with sap extracted from 30 to 100-year-old trees during late winter and early spring. The sugar maple is also one of the acer species that contributes to the jaw-dropping fiery colours of New England’s fall. In Japan, the turning of the maple leaves in autumn is almost as celebrated as the cherry blossom opening in spring: at temples, such as Bishamondo in Kyoto, acers blaze red under the grey skies, drawing crowds. While here in Britain, the star is often our native field maple (A. campestre), which glows a mesmerising shade of yellow in the right conditions, transforming grim motorways into avenues of gold.
Which maples to grow
Being relatively compact, Japanese maples (Acer palmatum and A. japonicum) make great garden trees. For autumn colour, both ‘Ōsakazuki’ and ‘Chitose-yama’ blaze incredible shades of scarlet before their leaves drop, while ‘Orange Dream’ and ‘Katsura’ take on lovely copper and apricot tones. Slow-growing, they only manage around 2 metres tall and wide in 10 years, but will eventually grow to 3 metres or more. Multi-season star ‘Sango-kaku’ can reach 6 metres in time, but deserves the space, producing pink-gold leaves in spring that fade to lime and glow butterscotch before falling to reveal wonderful coral-coloured winter bark. ‘Bi Ho’ provides similar leaf colours, with yellow-amber bark, and, being very small, is ideal for a container.
If the hemp-like leaf shape of most Japanese acers doesn’t appeal, there are exceptions: for instance, the dancing peacock maple, ‘Aconitifolium’ (syn. ‘Maiku Jaku’), has big fern-like foliage, and the leaves of ‘Vitifolium’ resemble a vine; both blush fabulous shades of crimson, purple, and orange in autumn.
But the Japanese maples are not the only acers that make good garden trees. The Amur maple A. tataricum subsp. ginnala ‘Flame’ is a spreading tree with rich-red autumn leaves that copes well with drought. The paperbark maple (A. griseum) has fiery autumn leaves and gorgeous cinnamon-coloured peeling bark that brightens the winter garden. Also boasting beautiful trunks are the striped snakebark maples (A. x conspicuum and A. tegmentosum), such as ‘Phoenix’, which has pink and amber bark during the cold months, and ivory and green ‘White Tigress’, which Roy Lancaster has named as his favourite plant. All are slow-growing to 6 metres or more.
For the larger garden, the box elder (A. negundo var. violaceum) has weird and wonderful pink-purple tassel flowers in spring, and the red maple A. rubrum ‘October Glory’ burns ruby red before the leaves fall. Our native field maple (A. campestre) is also a big tree eventually, with the species producing luminous-gold leaves and the variety ‘Evenley Red’ glowing garnet in the October light.
Where to plant acers
For most maples, choose a spot in sheltered semi-shade to prevent the leaves being scorched by cold winds and hot sun. Red-leaved forms (such as ‘Bloodgood’), however, are able to cope with stronger light. The soil should be well-drained and moisture retentive, so dig in organic matter (such as peat-free compost) before planting. Many acers (including Japanese forms) require a neutral to acid pH, so, if you are on alkaline soil, they are best grown in well-drained containers with a mix of ericaceous and John Innes No 3 composts. However, there are plenty of acers, such as field maples (A. campestre), that do not require acid soil. Field maples are also great plants for an exposed site and work well in a mixed hedge. Amur maples will also tolerate an exposed position.
How to grow acers
In the right conditions, maples are low-maintenance, no-fuss trees. Most do not like or require a lot of pruning, but select branches can be removed to shape the shrubbier Japanese forms into attractive multi-trunked trees, and dead wood should be cut out. Protect young and container-grown acers from winter weather by wrapping them in horticultural fleece.
Acer pests and diseases
Verticillium wilt, aphids, and horse chestnut scale can affect maples.
