Japanese maple is native to Japan, Korea, and China and is a popular bonsai material.
Japanese maple is a very desirable tree for bonsai because of its open growing habits and soft green (or bright red) leaves. Fall colors can be yellow, orange, and red, and some varieties have coral-red bark in the winter for silhouette viewing during the winter season.
There are many named varieties of Japanese maple, chosen for leaf color, growing habits, and bark characteristics.
Unfortunately, most of the selected cultivar trees are grafted, which requires an extra step to air-layer above the graft mark to eliminate the unsightly union.
Collecting
Japanese maple is a common landscaping tree and can be found in nurseries. Seed-grown varieties can be quite inexpensive and can be made into bonsai quickly without having to eliminate the graft union.
Choose trees with small leaves to start your bonsai, especially if your goal is a bonsai of modest size. (Note: not all dwarf maples have small leaves; "dwarf" could mean slow or congested growth, which may not be a desirable characteristic for bonsai.)
The best time to buy is in the fall before leaves drop, allowing you to select for fall color, leaf size, and growing habits. Choose a tree with the characteristics that appeal to you to make into a bonsai.
Environment
Japanese maple grows vigorously in full sun and thrives with ample water. They are often kept in partial shade to avoid leaf burns during the hot months, especially on hot, dry days in the fall.
It is a good practice to rotate your maple bonsai from time to time to ensure even exposure for even growth.
Styling
Japanese maple grows at a modest rate and is often made into formal and informal upright bonsai and forest groves. There is no reason not to attempt a design of your own creativity.
Pruning
It is easy to shape Japanese maple by pruning. Cut branches cleanly to the base instead of leaving a stub to make a jin because the wood is brittle and breaks off in nature.
Once your tree has taken on its fall color, the leaves are no longer photosynthesizing, and it is safe to prune heavy branches. This is also a time when you don’t have to worry about sap “bleeding” as in the active growing season.
Wiring
Make sure the wire is sufficiently stiff to hold the branch (10 to 18 gauge) and also wrap the wire loosely enough to accommodate rapid branch growth in the spring. Guy wires can be used effectively to simulate naturally drooping branches.
Trimming
Leaves can be trimmed on a healthy tree after the first flush of spring growth has hardened off. This encourages light and air into the interior of the tree's branches to promote growth.
Using snippers, trim off the branchlets to the right length above a bud. Given that buds are paired on opposite sides of the branch, you can cut off one of the buds to direct growth. This is an aspect of the clip-and-grow method.
Consider defoliating Japanese maple bonsai completely before clipping in late summer to give the entire tree a uniform appearance with its last flush of growth.
Pot/Repotting
Deciduous trees with fall color look good in complementary-colored pots: blue, cream, yellow, etc. Choose a pot style that is appropriate for the tree, which could also mean a pot that appeals to you.
The BH standard soil mix combined with the BH patent-pending pot should work well for Japanese maple. The built-in retainer well in the BH proprietary pot allows time for the root ball to absorb residual water.
The best time to repot your Japanese bonsai tree is from late fall to spring in mild climates, and in early spring to avoid roots freezing in colder regions. Wait until leaf buds start to "shine" and expand slightly.
Watering
Your watering routine must take into consideration soil composition, sunlight, and weather conditions. The standard BH soil mix is ideal for Japanese maple because it retains moisture and provides ample pores to supply oxygen to the roots as water evaporates. That soil mix, combined with the water retention feature of the BH pots, works well for Japanese maple bonsai.
Count on watering at least once a day. Water thoroughly to allow the root ball time to absorb water, especially when the surface of the soil feels dry. Avoid watering the leaves to prevent hard water spots and fungal infections in humid areas.
Water your bonsai well in the fall to keep leaves on the tree longer, giving time to display its fall color before they drop.
Fertilizing
Japanese maples respond well to fertilization. Use half-strength fertilizer as recommended to avoid over-fertilization.
Pest Management
Japanese maple trees are relatively disease-resistant and free from pests. Aphids can be a problem and are best controlled with a sharp spray of water or a spray of malathion. Eliminating any ants that encourage aphids is important—try Amdro bait products. Fungal leaf infections can occur in humid environments. Try BioAdvanced 3-in-1 Rose and Flower granules to help control fungus.
Propagation
Collect Japanese maple seeds in the fall, store them in the fridge, and plant them in the spring.
Japanese maple roots readily with both softwood and hardwood cuttings, as well as by air-layering.
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