Add a splash of colour to your garden with decorative Japanese maples. These ornamental trees may be short in stature, but they make up for it with their dazzling foliage. From soft pink to blazing red, deep purple to zingy lime green, these chameleons of the plant world add instant impact to any sized garden.
Japanese maples are ornamental trees with delicate foliage that are perfectly suited to pots and small gardens. Their colour-changing foliage comes in many shades, from lime green to vibrant orange or deep purple, and there are many variegated varieties. Some acers have upright habits, while others have weeping branches that look as beautiful when bare in winter as in summer.
Japanese maples are slow growing but long lived. Larger specimens can grow up to eight metres, but most only reach around two metres in height. There are a huge variety of acers available; if you're struggling to choose, read my guide to finding the best acer for your garden.
Where to plant acers
Japanese maples grow naturally on the edges of forests and hilly areas. This means they prefer dappled or partial shade and some shelter from cold winds. Some acers can tolerate more sun than others; Acer palmatum 'Bloodgood' is a good choice for sunnier gardens, and along with other purple and red-leaved acers, it needs some sun for its leaf colour to develop. Variegated and green-leaved varieties are more at risk of scorched leaves, and will look best if they get some afternoon shade.
Japanese acers can tolerate a range of soil types, but they prefer slightly acidic, fertile soil that's moist but well drained. If you have alkaline, chalky soil, you may be better off growing acers in pots rather than planting them in the ground.
Acers are featured in most Japanese garden designs, but they also suit contemporary, courtyard and woodland gardens. Use a single acer as a centerpiece or statement plant in a patio garden or front garden, or plant Japanese trees with contrasting foliage around a pond or seating area.
When to plant Japanese maples
Japanese maples are best planted between October and March. Avoid planting when the ground is frozen.
How to plant an acer tree
Water your acer in its pot about half an hour before planting. While you're waiting, loosen the soil in the planting area. Make sure you give your Japanese maple plenty of space, as they have shallow root systems and don't like competition.
Dig a hole as deep as the container your tree came in and around three times as wide. Remove the tree from its pot and position it in the hole so the top of the roots (where they join the trunk) will be level with the soil surface. There should be no more than an inch of soil over the main roots. Fill in the hole, gently firm the soil and water the ground. Add a thick layer of mulch, such as compost or bark, around the tree, making sure it doesn't touch the trunk.
Most Japanese maples don't require staking, but if you've bought a larger specimen, it will need some support while it establishes a strong root system.
Planting acers in containers
Japanese maples are the perfect tree to grow in pots, and with a bit of care, your acer will live a long and happy life in its container. It's best to gradually increase the size of the pot as your Japanese acer matures, rather than planting a very young tree in a large pot.
Choose a container no more than twice the size of the pot your tree came in. Make sure there are drainage holes at the bottom, as the roots could rot if the compost becomes waterlogged. Use a mix of peat-free compost with added John Innes and ericaceous compost, with some sharp sand mixed in for drainage.
Part fill your pot with compost, then remove your acer tree from its growing pot and position it in the centre of the container. Add more compost to fill the space around it and gently firm it down. Water your tree well and add some gravel, bark or other decorative mulch.
You'll need to move your Japanese maple into a larger pot every few years as it grows. The best time to do this is in spring, around April time, or early autumn. If you have a mature acer that's become pot-bound, you can lift it from its container and prune the roots in late winter, when the tree is dormant. Repot the tree with fresh compost and in spring, add some slow-release fertiliser.
How to care for Japanese maples
Trees need consistently moist soil for the first few years. Water your acer tree regularly during dry spells and droughts. It's best to water deeply once a week rather than a little every few days. Japanese maples grown in the ground don't need feeding, though they will benefit from mulching in spring to suppress weeds and keep the soil moist. They are hardy trees and don't require any winter protection.
Acers grown in pots need regular watering to prevent the compost from drying out. Use rainwater rather than tap water if possible. Add a slow release fertiliser to the pot in spring. In winter, raise the container on pot feet or bricks so the compost doesn't get waterlogged. You may also need to wrap the container in bubble wrap or hessian to protect the pot and tree roots during cold snaps.
How to prune an acer
Most Japanese maples naturally form an elegant shape, requiring little pruning. If you do need to prune your acer, it's best to do this in late summer or autumn, before the sap begins to rise. Focus on removing any dead or damaged wood and crossing branches. Prune branches back to a side branch to avoid leaving dead wood that can be prone to disease.
How to propagate acers
Japanese maples are tricky to propagate, as cuttings don't take very well. A more reliable method is to layer shoots in autumn or spring.
Choose a young shoot you can bend down to the ground (with length to spare) and make an incision across a leaf bud about a foot from the tip. Apply hormone rooting powder to the wound and bury it in a narrow trench in the soil. You'll need to peg the branch down to keep it in place. The tip of the shoot should point up out of the ground. Once roots have developed, in around 12 months, you can remove the shoot from the parent tree and replant it.
You can grow Japanese maples from seed, but the seedlings will look different to the parent plant and won't retain characteristics such as variegated leaves. Collect the winged seeds when they fall in autumn and plant them immediately in a seedbed or pots of compost. The seeds will germinate in spring.
Common problems
Most issues with Japanese maples arise from their planting environment; such as being planted in poor soil, full sun or exposed locations. Acers with finely dissected leaves are more at risk of leaf scorch, so take particular care when choosing a spot for these varieties. Young leaves can also suffer from frost damage, so you may want to cover trees with horticultural fleece if late frosts are forecast.
Scale insects may weaken young plants, though mature plants should be able to handle mild infestations. Encourage predatory insects, such as ladybirds, and remove any scales or eggs you spot.
Trees can be affected by fungal diseases such as Phytopthora root rot and verticillium wilt. Unfortunately, there's not much you can do to prevent these, but ensuring the soil is well drained can help.
Like many plants, Japanese acers grown in pots are susceptible to damage from vine weevil larvae.
Our favourite varieties of Japanese maple
Acer 'Taylor' is a stunning variety with unusual pale pink leaves. These turn green, with a cream margin, in summer before maturing to a vibrant lime green in autumn.
Acer 'Orange Dream' has vivid orange foliage in spring, which turns green in summer and bright yellow in autumn. This medium-sized tree is large enough to act as a focal point without overwhelming small gardens.
Acer 'Atropurpureum' is a purple Japanese maple with fiery red autumn foliage. To get the best colour from the leaves, make sure it gets plenty of sun.
Acer 'Emerald Lace' has finely dissected leaves that give the tree a light, feathery appearance. The foliage emerges lime green and develops a red edge through the summer, before giving a burst of orange-red colour in autumn.
FAQ
Do acers like shade?
Japanese maple trees prefer some shade, particularly from strong afternoon sun, but they won't thrive in deep shade. Light or dappled shade is ideal. Acers with red or purple foliage need some sun to get the best colour. Acer palmatum 'Dissectum' and Acer 'Butterfly' are good options for shady gardens.
Are acers evergreen?
No, acers are deciduous trees, meaning they lose their leaves in autumn. Many Japanese maples provide winter interest even after dropping their leaves; Acer 'Sango-Kaku' has coral-pink branches and stems that add valuable winter colour to your garden, and weeping Japanese maples such as Acer palmatum 'Garnet' have elegant drooping branches that look as attractive when bare as when covered in leaves.
How do I prune a Japanese maple?
Japanese maples require little pruning, as they are naturally very shapely trees. Carry out pruning between July and December, before the sap begins to rise in spring. Focus on removing any dead, damaged or diseased branches and any stems that cross or rub against others. If you want to shorten long branches, cut these back to a side branch.
