Japanese maple

A Japanese maple bonsai is the tree for anyone who loves the seasons: soft green in spring, a dense canopy in summer and, in autumn, a firework of yellow, orange and red. One thing first: the Japanese maple is an outdoor tree. It needs the change of seasons and a proper winter rest. Once you know that, it is a rewarding companion.

The right spot

Keep your Japanese maple outside all year, for example on a balcony, patio or in the garden.

• Partial shade is ideal: morning sun is fine, but strong midday sun in summer is not. The thin leaves scorch quickly and get brown, crispy edges.
• Sheltered from wind: dry wind pulls water out of the leaves, which also causes brown edges. A corner with some protection from a wall or hedge is perfect.
• Not too dark: in deep shade it grows weakly and the autumn colour stays dull.

Rule of thumb: in spring it can take more sun; from midsummer on, shade it around midday.

Watering and feeding

A Japanese maple in a shallow bonsai pot dries out fast. It likes to be evenly moist, but never soggy.

• In summer, check every day with your finger whether the top of the soil is getting dry. On hot days you may need to water twice.
• Never let the soil dry out completely. Drought stress shows up straight away as scorched leaves.
• Avoid waterlogging: the pot needs drainage holes and the soil must be loose and free-draining.
• In winter, without leaves, it needs much less water, but the root ball still must not dry out completely.

You will find more on spotting the right moment in our guide to watering bonsai.

Feed during the growing season from spring into early autumn. Use a mild fertiliser and not too much nitrogen, otherwise leaves and shoots get unnecessarily large. Stop in autumn so the tree can prepare for winter.

Pruning: timing is everything

With a Japanese maple, when you cut matters most.

• Trim shoots in spring: as new shoots grow, cut them back to one or two pairs of leaves. This keeps the tree compact and makes it branch more finely.
• Thicker branches after leaf fall: do bigger cuts in late autumn or early winter, once the leaves have dropped. You can see the branches clearly then.
• Not in late winter or early spring: maples "bleed" heavily at that time, which means a lot of sap runs out of fresh cuts. That weakens the tree for no reason.
• For larger wounds, use cut paste, a paste that covers and protects the wound.

For clean cuts, a good, sharp pair of scissors is enough at first. Our guide to bonsai tools for beginners shows what you really need.

Wiring, which means bending branches into shape with wire, is easiest in winter without leaves or in late spring once the new leaves have hardened. The bark is thin, so check often and remove the wire as soon as it starts to cut in.

Repotting and winter care

Repot a young Japanese maple about every two years, older trees less often. The best time is early spring, when the buds are just starting to swell. Use loose, free-draining bonsai soil.

Winter: the Japanese maple is frost hardy and needs the cold as a rest period. So it does not belong in a warm living room in winter. The roots in a small pot are more sensitive than in garden soil, though. In hard, long frosts, give it shelter, for example against a house wall, in an unheated shed or in a cold frame. Remember to water when the soil gets dry.

Which Japanese maple suits you?

When shopping you will also see cut-leaf maples with very fine, deeply divided leaves (dissectum varieties). They are beautiful, but usually grow in a weeping shape and are often grafted, meaning joined onto different roots. As bonsai they are harder to shape. For your first tree, choose a Japanese maple with normal, hand-shaped leaves and an upright habit. Also look for healthy buds and a sturdy trunk. More tips are in our guide to buying a bonsai.

Common problems

• Brown, crispy leaf edges: almost always too much sun, wind or too little water. Move it to more shade and water more regularly.
• Aphids in spring: they like the young shoots. Rinse them off or use a suitable spray.
• Leaves dropping in autumn: completely normal. The Japanese maple loses its leaves for winter.

In Japan

In Japan the Japanese maple is called イロハモミジ (iroha-momiji), often simply 紅葉 (momiji). The word "momiji" comes from an old verb for leaves changing colour in autumn. The same characters can also be read "kōyō", meaning autumn foliage in general. The name "iroha" is said to come from counting the pointed leaf lobes with the first syllables of an old Japanese syllable poem: i, ro, ha, ni, ho, he, to. Another word for maple is 楓 (kaede), traced back to "kaeru-de", "frog's hand", because the leaf looks like one.

In autumn, many people head out for 紅葉狩り (momijigari), literally "autumn leaf hunting". Of course nobody hunts anything: it means going out to admire the colourful leaves. The custom is considered very old and is said to have started among the nobility of the Heian period. Why it is called "hunting" is not entirely clear. One story goes that nobles saw walking into the mountains as something like a hunting trip. Only later did the autumn outing become a pastime for everyone.

A Japanese maple bonsai brings a little piece of Japanese autumn right onto your balcony. See what to do when in our bonsai calendar.