Japanese maple bonsai trees are quite popular for their eye-striking colorful leaves year-round. They can easily brighten and create a lively atmosphere in any space, making them an easy favorite of many bonsai enthusiasts.

To grow Japanese maples in your garden, you must learn how to care for and maintain such trees properly.

That being said…

Continue reading to know:

• The natural habitat and growth habits of Japanese maple trees.
• An extensive guide on how to care for Japanese maple bonsai trees.
• Several different Japanese maple varieties that are cultivated for bonsai growing.
• And much, much more…

General Information about Japanese Maple Trees

Botanical name:	Acer palmatum
Family:	Sapindaceae (Soapberry)
Tree type:	Broadleaf deciduous tree or shrub
Foliage type:	Palmately lobed with 5, 7, or 9 acutely pointed lobes
Growth habit:	Upright, cascading, or weeping
Native habitat:	Across hills of East Asia (particularly in Japan, Korea, and China)
Distinctive feature:	Brightly colorful fall foliage

Japanese maples are famous among locals and foreigners in Japan due to their striking fall color. 

It’s so popular that there’s an actual activity called Momiji-gari (autumn leaves-hunting), wherein groups of people visit natural parks or forests in Japan to view the astonishing fall colors of Japanese maple trees.

It’s also often present in traditional Japanese landscapes or gardens.

Name origin

A Japanese maple tree is also referred to as “Acer palmatum” due to its hand-shaped leaves. In Latin, “palma” means “hand palm,” hence the name.

In Japan, locals call it “momoji.”

Description

Japanese maples thrive mostly across hills in Japan, Korea, and China.

In nature, it can grow as a shrub or a small tree about 49 ft (15 m) tall. Since it grows under the shade of larger trees, it’s significantly more shade-tolerant than other deciduous species.

It usually has several trunks and a wide canopy that could be round or vase-shaped—some could also be in a weeping form. Its trunks and older branches are smooth and light gray, while its young shoots are either green, pink, or red.

The color, shape, and texture of Japanese maple leaves differ depending on the cultivar. They’re also smaller than other maples and leaf out early in the season.

Some cultivars have wide lobes, and others have lacy foliage.

Different Japanese maples showcase various fall colors that range from light green, golden yellow, orange-red, bright crimson red, and reddish-purple—with red cultivars being the most popular.

Note: Some Japanese maple species also have variegated leaves.

During spring, Japanese maples produce tiny, reddish-purple, five-petal flowers that appear in clusters.

Here’s a photo of a Japanese maple tree with light green leaves and purple-red flowers:

Then, in the fall, these flowers turn into half-inch-long dry-winged seeds called samara that twirl down like propellers as they drop to the ground.

See the image below:

Japanese Maples Cultivated for Bonsai

Japanese maples or Acer palmatum is a common and popular bonsai tree species in and outside Japan. 

That’s because it can be displayed as a centerpiece, an accent plant, or with other bonsai species such as azaleas, conifers, ginkgos, and rhododendrons.

Although there are hundreds of Japanese maple cultivars you can grow as a bonsai, most bonsai artists prefer smaller varieties so that it’s easier to maintain.

Here are some of them:

Growing Japanese maples as bonsai

You can propagate most Japanese maples by planting seeds in the fall, creating air layering or softwood cutting in the summer, or performing grafting in winter.

However, since Acer palmatum is a slow-growing species, it would be more practical to cultivate mature specimens to achieve an established look much faster.

Once you have your material, repot it in better soil and pot in the fall. Doing this helps the roots to gradually adapt to their new environment while the rest of the tree remains dormant.

How to Care for a Japanese Maple Bonsai

Japanese maple is a hardy tree that anyone can easily grow as long as it’s given the proper care and nutrients.

If you want your Japanese maples to thrive, check the comprehensive care guide below.

Quick general care guide for Japanese maple bonsai trees:

• Positioning: Place it outdoors year-round.
• Watering: Water it as needed—once the soil becomes slightly dry.
• Feeding: Fertilize once the new growth has completely hardened off.
• Pruning: Do as necessary and as desired in late spring or early summer.
• Wiring: Can be done anytime in spring or late winter.
• Repotting: Repot after 2 to 4 years as needed during early spring.
• Overwintering: Move in a cold frame once the temperature dips below 15 °F (-10 °C).

I. Positioning

Japanese maples are outdoor bonsai species. It means that it thrives outdoors with full sun and good air circulation.

However, like most tree species, too much heat due to direct sunlight can cause leaf scorch, especially during summer. Hence, you must place your Japanese maple bonsai in a spot with afternoon shade.

Note: Red-leaf specimens are more prone to leaf scorch than other varieties.

If you live in a zone with hot, dry climates, you want to choose varieties that have green leaves, as they can tolerate heat and high humidity way better.

II. Watering

Japanese maples don’t like short periods of droughts. That’s why you should water it thoroughly regularly, especially when it’s in full sun in summer. Water it once the soil becomes slightly dry.

If the soil is drying up too quickly due to extreme heat, cover the top layer of the soil with mulch or moss to retain moisture longer.

Misting the leaves as you water also helps raise the humidity level around the tree.

Another thing that you should keep in mind is that Acer palmatum trees don’t like calcareous water. When watering your small tree, use neutral or slightly acidic water. 

Watering Japanese maples based on the season

Depending on the season, your Japanese maple bonsai may need little or more watering. 

To ensure that your wonderful tree is nurtured properly, check out this guide:

A. In spring

Watering is crucial in spring as this is when new growth appears, requiring the tree to absorb more water.

That being said, check your bonsai at least twice a day. Then, water it thoroughly whenever the soil becomes slightly dry.

B. In summer

During this time, the new buds that appeared in the spring harden off. The water intake of Japanese maples slightly decrease.

Continue to check its soil twice a day and water as necessary.

C. In autumn and winter

Japanese maples drop their leaves in the fall and remain bald in winter, further decreasing the tree’s water intake.

Given that, you should reduce your watering frequency once every few days.

III. Fertilizing

You should only fertilize Japanese maples once the first flush of growth in spring has completely hardened off. Otherwise, it would cause the shoots and leaves to grow large.

Suppose you’re defoliating in mid-spring. Delay fertilization and wait until the second flush of growth has hardened off.

Tip: Opt for fertilizers with low nitrogen (N) content, as nitrogen promotes longer shoots and larger leaves, which you wouldn’t want for your small tree.

The frequency and amount of fertilizers should always depend on the health and needs of your tree. To ensure that you’re feeding your tree properly, check this guide:

A. For health enhancement

If your Acer palmatum bonsai is in its early development or suffering from poor health, you should increase fertilization to promote stronger and faster growth.

Use slow-release pellets to avoid root burn. You may also apply liquid fertilizer once a week for better results.

Note: The frequency of application and amount of fertilizers to put depends on the product you’re using. Check the packing of your bonsai fertilizer for instructions. 

For newly planted or repotted plants, wait until late winter or next spring.

B. For general development

As your tree matures, you can reduce the number of fertilizers you’re applying but continue to fertilize your tree as scheduled. 

IV. Pruning

Japanese maples are sturdy, so they can be trimmed year-round to maintain the shape of their canopy.

Since it’s a shrubby tree, it may suffer from dieback due to the lack of light and air in the inner buds and branches. To avoid that, thin out the branches and cut back leaves from time to time.

In May, cut off one uppermost leaf in each pair on the outer canopy to allow light and air to pass through. If that doesn’t help, you can cut the remaining leaf in half using a sharp pair of pruning shears.

Defoliation

Strong and healthy trees can also be defoliated to encourage finer ramifications and promote new growth. Full defoliation can be done every 2 to 3 years, and 80% to 90% partial defoliation can be done yearly. 

When doing partial defoliation, leave some foliage on branches you want to develop or thicken up. Also, remove too large and closely-spaced leaves to create energy balance.

Removing branches

Remove small lower branches and shoots from the base to create a canopy or rounded tree. Doing this prevents such areas from developing and potentially overpowering main branches.

If you want to prune strong branches, do it in summer or fall to prevent excess sap bleeding. Then, apply a thin layer of cut paste on the wounds to promote faster healing and fungal disease infections.

V. Wiring and Bending

Depending on your tree variety, you may find wiring and styling your bonsai easier in late spring or winter.

To wire and style Japanese maples properly:

1. Slightly bend the inner branch upward.
2. Bend the outer part of the same branch slightly downward.
3. Point the tip of the branch upward. The branch should appear wavy.
4. Next, fan out the internodes to showcase its fine branchings.
5. Repeat steps 1-3 to all the branches, then position them as desired.
6. Finally, wire the smaller upper branches upward to create an apex.

Note: Use aluminum wires on Japanese maples and apply them at 45 to 50 degrees.

Check the wires at least once a month to avoid them from biting into the branches and causing scars. Once they start to bite in, carefully remove the wires using a bonsai wire cutter.

You can also watch this video to learn how to properly and safely wire Japanese maple bonsai trees further:

VI. Repotting

Since Acer palmatum bonsai trees are slow growing, you’d only need to repot your tree about every two years.

Repot in early spring just as the buds begin to swell to avoid dieback. 

Once the leaf shape is fully revealed, consider it too late. Delay repotting until the coming fall or the next early spring.

Soil and pot requirements

Japanese maples prefer moist, slightly acidic, and well-drained soil. That said, use a bonsai soil mixture with moisture-retaining substrates, such as pine bark.

If you have an upright tree, plant it in a shallow bonsai pot with drainage holes. Plant it in a deeper but narrower pot if it has a cascading form.

Also, ensure it’s planted in a bonsai pot with drainage holes to drain excess water and prevent waterlogging.

VII. Winter Care

Although Japanese maples are known to be frost-hardy, they still require some protection from spring frosts and strong winds.

Once the temperature drops below 15 °F (-10 °C), do either the following:

• Place it in a cold frame.
• Move it to an unheated room, such as a garage.
• Wrap the pot in burlap to protect the roots from cold.

VIII. Pests and Diseases

Although it’s a hardy species, a Japanese maple bonsai can still be infested and infected by certain pests and diseases.

Yellowing of leaves, crinkled leaves, or dark spots on leaf tips may be signs of infections that can cause your bonsai to die when not treated.

Some common issues with Japanese maple bonsai trees:

1. Aphids & scales – sap-sucking insects that mostly appear in spring. You can eliminate them by washing them off with water or using insecticides.
2. Abnormal yellowing of leaves – can be due to nutrient deficiency, overwatering or underwatering, or fungal disease.
3. Verticillium wilt – a fungal disease that causes dead leaves and dieback. Since it has no treatment, you can only eliminate it by discarding the affected plant and contaminated soil. Clean your bonsai tools to prevent the disease from spreading to other healthy trees.

Conclusion 

Japanese maples are adored for their striking fall colors that range from green to yellow, orange, crimson tones, and deep maroon—making them popular in many Japanese gardens and natural parks.

Since Japanese maples grow slowly, they make a perfect specimen for bonsai growing. As long as they are provided with proper care and nutrients, they can grow tall and wide despite being constrained in small spaces.

That’s all! I hope this comprehensive care guide has helped you in your bonsai journey.