How to Grow and Care for Japanese Maple Bonsai

Bonsai is the ancient Japanese art form of growing ornamental miniature or artificially dwarfed trees in containers using cultivation techniques designed to mimic the shape and scale of full-sized trees.

Japanese maples are some of the most dazzling trees for bonsai and are widely popular thanks to their brilliantly colored fall foliage and ease of care. These compact trees offer a moderate growth habit that slows with age. The broadly spreading crown features layered branching with the signature palm-shaped leaves.

Unlike some other bonsai specimens, Japanese maple bonsai are great for beginners and do not require as much care and skill to keep happy.

Another benefit of the Japanese maple bonsai is that it does not require as much sunlight as most other bonsai varieties. The fine, delicate branches are flexible and easy to shape, lending themselves well to the techniques involved in bonsai training.

Japanese Maple Bonsai Care

Japanese maple bonsai are relatively easy to care for and make great bonsai for beginners and professionals alike. They are characterized by a moderate growth rate and can be easily trained through regular pruning and wiring.

Wiring a Japanese maple bonsai should be done in the summer months while the tree still has all of its leaves, and the wires should not be left on for more than six months at a time.

In general, Japanese maples respond very well to wiring as their branches are flexible and easily shaped. As always, it’s best to take it slow and not overdo the wiring, as you don’t want to damage the tree. 

Light

Japanese maple bonsai do not need as much sunlight as some bonsai specimens do. This makes them perfect for gardeners with partly shady backyards.

They should be protected from the harsh midday rays and do best when positioned in locations that receive morning and evening sun and dappled sun throughout the rest of the day. They especially need shade during hot summer months when too much sunlight may scorch leaves.

Soil

Japanese maple bonsai require well-draining, nutrient-rich soil with a pH between 5.5 and 6.5 in order to thrive.

Generally, using a commercially available bonsai soil mix is best, as they are specially formulated to support the growth of bonsai trees.

Water

In general, bonsai trees require a significant amount of moisture in order to survive, and Japanese maples are no exception. During the spring and summer months, these trees may need to be watered as often as every day, although they will require significantly less water during the fall and winter months. The soil should be kept evenly moist at all times during the spring and summer, but never waterlogged, which can cause the roots to rot.

Temperature and Humidity

As with most bonsai trees, Japanese maple bonsai are best suited to outdoor growing and do not grow well indoors.

Although they are native to Japan, they are adaptable to a wide range of climates in North America, Europe, China, and Korea. While they are cold-hardy trees, they can only tolerate short periods of freezing temperatures and should be protected from harsh winter climates.

Fertilizer

Japanese maple bonsai require regular fertilizing to encourage strong and consistent new growth.

During the spring and summer, feed Japanese maple bonsai every other week with an organic bonsai fertilizer or liquid fertilizer. During the fall, switch to a nitrogen-free fertilizer and cut back on the frequency of feeding.

Avoid feeding for several weeks after repotting a Japanese maple bonsai to allow the delicate roots to regrow without the risk of shock.

Varieties of Japanese Maple for Bonsai

There are several varieties of Japanese maple that are suitable for bonsai cultivation and training. The following are some of the most common and popular types for bonsai:

• Acer palmatum ‘Deshojo’
• Acer palmatum ‘Arakawa’
• Acer palmatum ‘Seigen’
• Acer palmatum ‘Katsura’
• Acer palmatum ‘Shishigashira’

Pruning

Regular pruning is essential for the aesthetic and health of a bonsai tree. In the spring and summer, the new shoots should be pinched back on a regular basis to shape the tree and encourage branching. The leaves of Japanese maple bonsai should also be actively pruned throughout the growing season to keep them small and match the shape of the overall tree.

As with most bonsai, any heavy pruning of main branches or stems should be saved for the late fall to winter months. 

Propagating Japanese Maple Bonsai

Many of the amazing-looking Japanese maple bonsai varieties have been grafted. Taking cuttings from a Japanese maple tree, or collecting its seeds for propagation won't produce a tree with the same characteristics as the bonsai tree you are after. And even if you are ready to take your chances with seeds, it takes at least three years for a young seedling to reach the stage where you can start shaping it. Therefore propagating your own Japanese maple bonsai is not recommended.

Potting and Repotting

Generally, as with most bonsai, the Japanese maple variety does not need to be repotted often once it is well-established. When the tree reaches 10 years old, repot every three years. However, young trees benefit from yearly repotting to help refresh the soil and prune the rootball. Using bonsai pots will help to achieve the bonsai aesthetic, and restrict the tree’s growth over time.

The best time to repot Japanese maple bonsai is in the spring months just before the buds have opened. This will help to ensure that the tree has adequate time to recover from the repotting before it goes into dormancy in the fall and winter months.

Japanese maple bonsai grow roots quickly and vigorously and will require root pruning at the time of repotting. Cut back up to ⅓ of the roots, starting from the outside and moving inwards. Avoid chopping any large, main roots as you don’t want to disturb the main system.

Overwintering

If winter temperatures in your area drop down to 25 degrees Fahrenheit or below, the tree needs protection from the cold, as well as strong winds. Put it in a sheltered location outdoors. If winter temperatures in your area drop even lower, below 15 degrees Fahrenheit, you also need to insulate the roots, either by burying the pot in garden soil for the winter, or place some other insulating material such as bubble wrap or burlap around the pot. As the tree goes dormant, it won't need much watering; water it only when the soil dries out.

Common Pests & Plant Diseases

Japanese maple bonsai are susceptible to a few common pests and diseases. Checking the tree regularly for signs of an infestation is the best way to help prevent damage from pests and diseases. In particular, keep an eye out for aphids, verticillium wilt, and powdery mildew.