Japanese Maple Tree Care And Growing Guide

What is Japanese Maple Tree?

The Japanese maple tree is a small deciduous tree native to Japan, Korea, China, and parts of Mongolia and Russia. This tree is celebrated for its stunning aesthetic appeal, particularly its leaves, which change color throughout the year, providing a spectacular display of reds, oranges, and yellows in the fall.

Trees, Japanese maple, hold significant cultural value in Japan, where they are often associated with beauty, tranquility, and the changing seasons. 

Tree Parts

The tree can be divided into the following parts:

• Leaves: The most distinctive and admired part of the Japanese maple, the leaves are typically palmate (hand-shaped) with five to nine-pointed lobes.
• Trunk and Bark: The tree usually has a smooth, gray bark that can develop interesting patterns and textures as it ages. The trunk is often short, with multiple branches that give the tree a graceful, spreading form.
• Flowers: Japanese maples produce small, inconspicuous flowers in the spring. They are usually red or purple and give way to winged seeds known as samaras.
• Samaras: These winged seeds spin like helicopter blades when they fall, aiding in wind dispersal. They are typically paired and resemble small, reddish propellers.
• Roots: Japanese maples have a relatively shallow root system that spreads out widely. This makes them susceptible to damage from heavy foot traffic or disturbance, but it also helps absorb water and nutrients efficiently from the upper soil layers.

Japanese Maple Care

Japanese maple trees are relatively easy to care for with some attention to their specific needs. Both young and mature trees require care, though the intensity of care decreases as the tree establishes itself and becomes more resilient.

Care of Japanese maple trees ensures their vibrant colors and healthy growth. Here’s an easy-to-understand guide to help you take good care of your trees:

Light

Japanese maple trees love partial shade. They enjoy some sunlight, especially in the morning, but too much hot afternoon sun can burn their delicate leaves. It's best to plant them where they get morning sun and afternoon shade.

Soil

These trees grow best in well-drained soil. They prefer soil that is slightly acidic or neutral. If your garden soil is heavy clay or very sandy, mix in some compost to improve it.

This will help the tree get the nutrients it needs and prevent water from pooling around the roots.

Water

When Japanese maple trees are young, they need regular watering to keep the soil moist but not soaked. Water them deeply once a week, making sure the water reaches the roots.

For mature trees, water deeply during dry periods. Always water at the base of the tree to keep the leaves dry and avoid fungal diseases.

Temperature

Japanese maple trees like moderate temperatures. They can handle some heat but need protection from extreme temperatures. In hot areas, give them some afternoon shade. In cold areas, plant them in a spot that shelters them from strong winds.

Humidity

These trees do well in moderate humidity. Avoid planting them in places that are very dry or very humid. Mulching around the tree helps keep the soil moist, which also helps maintain the right humidity level around the tree.

Fertilization

Fertilize your Japanese maple in early spring before new growth starts. Use a balanced, slow-release fertilizer to give it the nutrients it needs throughout the growing season. Be careful not to over-fertilize, as too much can harm the tree.

Pruning

Pruning maintains the shape, removes dead or diseased branches, and promotes healthy growth. The best time to prune is in late winter or early spring when the tree is dormant.

During this time, you can safely remove any crossing or rubbing branches, as well as any branches that are growing inward or downward.  Use sharp, clean pruning shears to make clean cuts, ensuring minimal damage to the tree.

Avoid pruning during the growing season, as this can lead to excessive bleeding and stress on the tree. Regular, light pruning can also be done in the summer to shape the tree and remove any small, unwanted branches.

Winter Care

Young Japanese maple trees need protection from frost in the winter. In cold areas, wrap the trunk with burlap or use a tree guard to protect it from freezing temperatures. Mulching can also help insulate the roots and keep them warm.

Mulch

Mulch is important for Japanese maple trees as it helps to retain soil moisture, regulate soil temperature, suppress weeds, and improve soil health. Use organic mulch, like wood chips or bark.

Make sure to keep the mulch a few inches away from the trunk to prevent rot and pests. Apply the mulch evenly, about 2-3 inches deep, covering the entire root zone of the tree.

Why Grow Japanese Maple Tree?

Growing a Japanese maple tree offers numerous benefits that make it a rewarding addition to any garden or landscape. Here are some compelling reasons to grow Japanese maple:

• Striking Autumn Shades: Japanese maples are famous for their vivid autumn leaves, showcasing a spectrum of rich colors such as red, purple, and orange.
• Compact Growth: The majority of Japanese maple varieties are relatively petite, reaching heights and widths of 15 to 25 feet. This compact size renders them suitable for small gardens and yards where larger trees may not be practical.
• Versatility: Japanese maples can thrive both on the ground and in containers. They serve as excellent subjects for bonsai cultivation and can enhance the aesthetic appeal of porches or entryways.
• Cultural Significance: Similar to cherry blossom viewing, the Japanese maple is admired during the autumn season in a practice known as "momijigari" or maple leaf viewing. This tradition involves visiting scenic areas to enjoy the vibrant fall foliage.
• Low Maintenance: Once established, Japanese maples are relatively low-maintenance trees. They do not require regular pruning, and with proper soil preparation and watering, they can thrive with minimal care.

Japanese Maple Tree Growing Guide

Japanese maple trees typically grow at a slow to moderate rate, with most varieties growing about 1 to 2 feet per year. This growth rate can vary depending on factors such as sunlight exposure, soil quality, and cultural practices.

If you want an established look right from the start, you can opt to plant an older, larger maple rather than a young one that may take years to mature.

When To Plant

Japanese maple trees are usually planted during the spring or fall to allow the roots to establish without facing extreme temperatures. Spring planting, favored for its moist soil and rapid growth before the summer heat, is optimal.

Fall planting is also viable, enabling the tree to settle before winter cold. Avoid planting during midsummer heat or midwinter cold to prevent stress or damage to the tree's roots.

Where To Plant

Japanese maples thrive in areas with filtered sunlight or partial sun. It's best to avoid places where the sun is intense, especially during the afternoon, as this can lead to leaf scorching.

Additionally, when planting, ensure they're positioned in a sheltered spot shielded from strong winds, ideally on the north or east side of a building.

They are typically grown outdoors in gardens and landscapes, however, certain varieties, such as compact and dwarf cultivars, 'Red Pygmy,' 'Shaina,' and 'Sharp's Pygmy', are ideal choices for indoor cultivation.

Potting and Repotting

When planting Japanese maple in a container, use a large pot with good drainage and an acidic soil mix. Repot every 2-3 years or when roots outgrow the container. Choose a slightly larger pot and a fresh soil mix, then water thoroughly after repotting. Keep an eye on growth and repot as needed for continued health.

How To Plant

Here is a step-by-step guide on how to plant a Japanese maple tree:

• Choose a location with suitable sunlight and protection from wind and frost. 
• Clear the planting area of weeds and enrich the sandy soil with organic matter, like compost.
• Make a hole twice as wide as the rootball and slightly shallower to aid drainage and prevent waterlogging.
• Place the tree in a strategic and visually pleasing position, considering its growth pattern and surroundings.
• Fill the hole with the original soil, avoiding amendments that can cause drainage issues.
• Give the tree a good soak after planting to compact the soil and remove air gaps.
• Spread 2-3 inches of organic mulch near the tree's base, ensuring it's a few inches away from the trunk.
• Water the tree every 2-3 days initially, then weekly if there's no rainfall after the first month.

Propagating Japanese Maple Tree

Propagation of Japanese maple trees is possible through various methods, including seeds, cuttings, and grafting. While seeds can be used to grow Japanese maple trees, they may not produce offspring identical to the parent tree, as Japanese maples are often hybrids or cultivars. 

For this reason, propagation through cuttings or grafting is preferred to maintain the characteristics of the parent tree.

Propagating through Cutting

Stem cuttings involve taking a cutting from a healthy stem, removing lower leaves, and rooting it in moist soil or water. This method is more challenging for certain cultivars, such as dissected leaf varieties, which have lower success rates. 

Propagating through Grafting

Grafting involves joining a cutting from a desired cultivar onto a rootstock, ensuring the desired traits are preserved. This method is commonly used for popular and valuable ornamental varieties.

Propagating through Air-Layering

This is another method used for propagation, where a portion of a branch is encouraged to form roots while still attached to the parent tree. Once roots have developed, the rooted portion can be separated and planted as a new tree. This method is often used for woody plants like Japanese maples.

Types of Japanese Maple

There are over a thousand varieties of Japanese maple trees, each with diverse characteristics such as leaf form, color, branch arrangement, and overall size. However, the vast majority of Japanese maples belong to just three main species:

1. Acer palmatum (Japanese maple)

This is the largest category, boasting numerous beloved cultivars. These trees are deciduous shrubs or small trees, typically growing in rounded to broad-rounded shapes with low branching that weeps elegantly. Their leaves are characterized by pointed, toothed lobes.

Native to Japan, Korea, and some parts of Mongolia and Russia, this tree variety thrives in USDA Zones 5–9. They typically grow 10–25 feet tall and wide, but there are dwarf varieties that do not exceed 4–15 feet.

Some examples include:

• Tamukeyama: A drooping variety with deep red leaves.
• Viridis: A drooping variety showcasing bright green leaves.
• Crimson Queen: A lace-leaf, drooping variety featuring rich red foliage.
• Bloodgood: An upright type with red leaves that deepen to dark green during summer.
• Sango-kaku (Coral Bark): An upright type displaying green leaves in summer and vivid coral-red bark in winter.

2. Acer japonicum (full moon maple)

Acer japonicum, commonly known as the Fullmoon Maple or Peacock Maple, is a slow-growing deciduous tree native to mountainous areas of Japan, Manchuria, and Korea.

It has rounded leaves with shallow lobes that turn yellow and red in the fall. The tree grows up to 15–30 feet tall and prefers cool summer conditions with lightly dappled shade. It is adaptable to many soil types but performs poorly south of USDA Zone 7. 

Popular types include:

• Aconitifolium: Known for its deeply incised leaves and intense fall coloration.
• Green Cascade: Features drooping to pendulous branches and is often used as a specimen tree.
• Vitifolium: Has grape-like leaves with shallow lobes and fall colors of purple, orange, and red.

3. Acer shirasawanum (Shirasawa maple)

Also referred to as the full moon maple, this species bears a resemblance to A. japonicum and is native to Japan. It is a deciduous shrub or small tree that grows up to 15-20 feet tall with a rounded shape and smooth bark.

The leaves are simple, opposite, and have 9–13 lobes with a doubly serrate margin. The leaves turn yellow, orange, and red in autumn. Some of its popular types are:

• Viridis: Weeping variety with bright green foliage

Common Pests and Diseases

Japanese maple trees can be susceptible to pests and diseases, although they are generally hardy when properly cared for. The main reason for susceptibility is often related to stress factors such as inadequate watering, poor soil conditions, and improper pruning.

Here are some common pests and plant diseases affecting Japanese maple varieties:

Common Pests

Common pests affecting Japanese maple trees include:

• Aphids: Aphids, small insects that feed on plant sap, can be prevented by maintaining your maple tree and keeping it free from debris.
• Scale insects: Scale insects attach to leaves and stems, causing damage; suffocate them with horticultural oil or insecticidal soap.
• Spider mites: Spider mites, which turn leaves yellow, can be controlled by dislodging them with a strong water blast.
• Japanese beetles: Japanese beetles, identified by their metallic bodies, can be prevented with barriers and insecticides.
• Borers: Borers tunnel into the bark, potentially killing the tree; prevent them with water and regular pesticide treatments. 
• Mealybugs: Mealybugs, tiny sap feeders, can be eliminated with insecticidal soap or neem oil.

Common Diseases

Common diseases affecting Japanese maple trees include:

• Powdery Mildew: A fungal disease causing a white powdery substance on leaves, manageable by brushing off fungus or horticultural oil.
• Verticillium wilt: A fungal disease leading to wilting and death, spread via contaminated soil, controlled by fungicides and sanitation.
• Anthracnose: a fungal disease creating dark lesions on leaves, stems, and branches, managed with fungicides and sanitation.
• Leaf Spot: A bacterial disease causing small, dark leaf spots, treatable by removing infected leaves and fungicides.
• Sapstreak: A fungal disease causing dark bark stains that spread through soil and is managed by root protection.