How to Grow and Care for Japanese Maple Trees

Japanese maple trees originated in East Asia and are often part of traditional Japanese landscaping and garden design. Japanese maples are commonly used in bonsai and are prized for their ease of care and beautiful fall leaf colors.

The size of the Japanese maple differs by variety and cultivar, ranging from 2 feet to 25 feet tall. These trees have a slow-to-medium growth rate, growing about 1 to 2 feet annually, depending on optimal growing conditions.

Japanese maple tree sizes can range from a miniature dwarf tree to a shrub to a small tree. The shape can be round, mounding, vase-like, cascading, or upright. Itmay also have a weeping form. Common varieties have descriptive names alluding to their coloration, like 'Bloodgood,' 'Crimson Queen,' and coral bark Japanese maple trees.

The Japanese maple tree is renowned for its striking leaves. Japanese maple leaves have five to ninepalmate lobes that may come in green or red (or both). In the fall, Japanese maple leaves turn to brilliant shades of red, orange, yellow, or purple, varying in texture with wide lobes, finely dissected lobes, and a lacy, wispy appearance. The small, inconspicuous flowers are red or purple; these become a dry, winged fruit or samaras—half-inch long helicopter seeds so named for how they spin in the wind when falling from trees.

Plant Japanese maple in the spring or fall. Give these trees extra attention in the first few years while they're getting established; after that, Japanese maple trees are easy-to-grow, low-maintenance, and hardy.

Pros and Cons of Growing Japanese Maple Trees

• Comes in many varieties, shapes, sizes

• Features ornamental leaves and colors

• Grows at a moderate rate

• Easy to care for

• Makes maple syrup

• Softwood is susceptible to wind damage and heavy snow

• Roots can crack sidewalks or driveways

• Shallow roots can make lawn mowing difficult

• Vulnerable to various pests and diseases

Planting Japanese Maple Tree

When planting a Japanese maple tree, consider the time of year, sunlight, soil condition, and wind exposure.

When to Plant

Spring and fall are the best planting times for Japanese maple trees. Spring might be slightly more advantageous, allowing the tree more time to develop roots before winter. Fall is trickier since the tree is most fragile in the first few years, especially around bitter winds or frigid temperatures. It will need winter protection in its first few years if you live in a freezing zone. If you get a tree for planting in summer or winter, do not plant it. Keep it contained with moist (not soggy) soil until fall or spring.

Where to Plant

A Japanese maple tree needs a spot where it will get dappled light or at least morning sun with afternoon shade. It will need protection from strong winds, such as the north or east side of a house or building, where it will only get morning sun. Intense sun can cause leaf scorch, which looks like a brown rim around the margins of the leaf. Its soil should be well-draining, acidic, and, compost-enriched.

How to Plant

Once you've found the perfect spot, dig a hole three times the width of the root ball. Set the root ball in the center of the hole, slightly above the soil line. Backfill what's left of the hole with the same soil. Water it thoroughly.

Container Planting

Japanese maple trees make good bonsai specimens because they will "self-stunt" or stop growing taller and wider once their roots have nowhere to go. If you plan on keeping your Japanese maple in a container, it's best to get a small or dwarf form. A larger variety might be more likely to get stressed if confined indefinitely. Trees with higher stress levels are more vulnerable to disease or insect infestations.

Japanese Maple Care Requirements

The Japanese maple is a small tree that will fit into almost any yard, and maples make a beautiful addition to any landscape design. While they have a reputation for being fussy, if you plant them in their preferred condition, they are not that difficult to care for, although they are slow-to-moderate in growth rate, so you'll need a bit of patience.

Light

Grow Japanese maple in filtered sun to part shade. It is a suitable tree for full shade if needed, especially in the warmer zones, but different cultivars have different needs, so do some research before getting one. Afternoon sun is rarely tolerated by any cultivar, often resulting in sunburnt Japanese maple leaves.

Soil

Japanese maple trees like moist, well-drained soil and compost-enriched soil. Loamy and sandy soil will work well, but avoid soil with high alkalinity; Japanese maples thrive in slightly acidic soil. Japanese maple trees can also grow in poor soil, but growth will be slower, and it can lead to the tree getting stressed out.

Water

Although Japanese maples prefer well-draining soil, they also like to receive regular water. The easiest way to regulate the soil's moisture level surrounding a Japanese maple is to mulch it. Until your tree is well-established, take the time to water it whenever the soil feels dry, particularly when it hasn't been raining much.

A newly planted tree needs water every 2 to 3 days for the first month. After that, it needs water at least once a week, especially without rain or snow.

Some anecdotal information suggests that cutting back water in late summer intensifies fall color. However, no scientific studies back the theory.

Temperature and Humidity

Red-leaf varieties are more prone to leaf scorch than green varieties, so in hot, dry climates, green-leaf varieties of Japanese maples are usually the better choice. The trees can usually withstand moderate humidity. Generally, Japanese maples do best in USDA zones 6 to 8 though some varieties thrive in zone 5. Protect your Japanese maple from areas that experience strong winds. Young trees will also need some winter protection in the first few years.

Fertilizer

Hold off on fertilizing a newly planted Japanese maple and only feed it in the late winter or early springof the second year. Instead, plant it with compost-enriched soil. Trees with healthy foliage planted in rich soil with plenty of organic matter do not need annual fertilization.

If you need to fertilize, do this in the spring. Apply a slow-release granular shrub and tree fertilizer and mix it at half the recommended rate for landscape trees. Do not apply liquid fertilizer, as it can burn the roots. Spread the fertilizer evenly around the tree, starting at least 1 foot away from the trunk and beyond the tree's drip line. As a rule of thumb, for every 5 feet in height, spread the fertilizer 1 foot beyond the drip line.

Mulch Cover

Since the Japanese maple tree roots are shallow, they benefit from a 3 to 6-inch layer of mulch covering the tree's base—spreading out a radius of about 6 inches. Start the mulch a few inches away from the tree trunk. New plantings especially need mulch to help keep the soil moist and insulate roots in winter. Mulch every one to two years, replenishing mulch over time.

Types of Japanese Maples

Hundreds of varieties and cultivars of Japanese maplesare in various sizes, colors, shapes, and leaf textures. Many cultivars stay under 8 feet. Some notable cultivars include:

• Acer palmatum'Coonara Pygmy': Dwarf maple; a good choice for growing in a container; pinkish leaves in the spring that turn orange-red in the fall
• Acer palmatum'Villa Taranto': Weeping Japanese maple; delicate leaves that turn golden yellow in the fall
• Acer palmatum'Wolff' (also known as 'Emperor I'): One of the best cultivars for USDA zone 5 (and maybe even zone 4); stunning purple foliage
• Acer palmatum'Sumi nagashi': Faster-growing cultivar; grows well in USDA zone 5
• Acer palmatum 'Red Dragon': Laceleaf weeping maple; bright red, cherry-colored leaves in the spring that become darker over the summer and turn scarlet in the fall
• Acer palmatum 'Bloodgood': Grows to 20 feet tall with a similar spread; has reddish-purple leaves in the summer and is greener in full sun; leaves deepen to crimson red in the fall
• Acer palmatum 'Crimson Queen': 8 to 10 feet tall with a spread of 10 to 12 feet; weeping habit and dissected leaf type; dark-red summer leaves deepen to crimson; fall colors include yellow, red, purple, and bronze
• Coral bark Japanese maple or Acer palmatum 'Sango Kaku': Small to medium-sized tree; prized for its coral-red bark; green leaves in spring and summer and golden leaves in fall

Pruning

Japanese maples need very little pruning. Never give severe pruning to any Japanese maple trees younger than 10 years old. Keep long, whip-like branches intact; they will grow beautifully in time.

For older, more established trees, only prune the lower branches and remove any crossed branches to improve appearance. Remove any dead, diseased, or damaged branches. You can also control the appearance of the Japanese maple by choosing whether to train a single trunk or to allow multiple trunks to form.

Propagating Japanese Maples

You can propagate a Japanese maple with softwood cuttings taken in the summer:

1. Using sharp shears, cut a 6- to 8-inch section of new growth that is hardened but still young enough to be pliable, not yet mature, and woody. Only keep the top sets of leaves and remove the rest.
2. Insert the cut end in a 4-inch pot filled with potting mix. For increased success with rooting, dip the cut end inrooting hormone.
3. Moisten with water, but don't oversaturate the soil.
4. Place the cutting in a location that gets bright, indirect light. Mist it twice a day. Roots should develop within three to four weeks.

Another, more involved method of propagating a Japanese maple is by grafting. It involves joining the rootstock of a closely related species with thescionor upper stock of the cultivar. Grafting is usually done in the winter:

1. Start with a two-year seedling that you previously started. The trunk must be at least 1/8-inch in diameter. You'll need a sharp grafting knife.
2. Pull the base plant out of dormancy for about a month by putting it in a warmer location.
3. Cut a splice graft in a long diagonal about an inch long. Take a cutting of the same diameter from the cultivar plant, intending to fit the two together.
4. Wrap the union with rubber grafting tape and secure the graft with grafting wax.
5. Place the grafted plant in a place that gets sun but is not too direct. Consider giving shade to prevent scorching the graft.
6. Recheck the wax in three to five days. You want to maintain a good seal and keep humidity high.
7. Prune off any growth coming from the rootstock.
8. Watch for new growth from the scion; that's a sign that the graft is successful.
9. Remove the wrapping once the scion develops leaves, preventing girdling.
10. Plant in the ground after a year of successful growth in the container.

Growing Japanese Maple Trees from Seed

As most Japanese maples sold are cultivars, the tree that will grow from its seeds will not have the same desirable features as the parent. Given the length of the process and the unpredictability of the result, it is not recommended to start a Japanese maple from seed but propagate it from cuttings instead.

Potting and Repotting Japanese Maples

Aside from their use in bonsai, dwarf Japanese maples can also be grown as container trees and moved about the yard throughout the season. Plant them in a container with adequate drainage holes since Japanese maples do not do well in soggy soil. Choose a well-draining high-quality potting soil. A terra-cotta pot works well as it wicks away extra moisture.

Repot once roots reach the sides and bottom of the pot or grow out of the drainage holes.

Overwintering

Mulching will help protect the tree's shallow roots. Japanese maples are hardy to USDA zone 5, but container plants need protection during the winter. Move the container to an outdoor location shielded from strong damaging winds.

To protect the roots against the cold (in a container, they are much less insulated than in garden soil), wrap the container in burlap and bubble wrap or protect it with an insulating silo. You can plant stakes around a newly planted or young tree and wrap burlap around it to give it a semi-shelter.

If a cold snap is expected in later winter or early spring and unseasonably warm temperatures have spurred your tree to set leaves, you can cover or wrap the tree with a tarp. An unexpected hard frost can kill the leaves and potentially freeze the sap in branch structures, killing the branches. If it's a young plant in a container, bring it indoors for the duration of the frigid temperatures.

Common Pests and Plant Diseases

Japanese maples are susceptible to various pests, including aphids, mealybugs,scale bugs, mites, borer, and Japanese beetles, which can defoliate a Japanese maple quickly. Aphids and mealybugs can be washed off with a garden hose. For the other pests, you might have to use insecticidal soap or neem oil, or if the infestation is so heavy that it cannot be treated with organic pesticides, use chemical pesticides as a last resort.

Japanese maples are also susceptible to cankers, verticillium wilt, a soil-borne fungus that leads to premature yellowing of the leaves and leaf drop, powdery mildew, anthracnose, and sooty mold.

How to Improve Common Problems with Japanese Maple

If your Japanese maple tree is struggling, it could also be one of these common issues:

Twig Kill

Twigs dying is usually a sign of insufficient water. Water the tree slowly but deeply to restore its vigor and repeat it regularly to prevent a recurrence.

Manganese Deficiency

The most common nutrient deficiency of Japanese maples is a lack of the micronutrient manganese, which manifests as yellow or yellowish-green leaves with darker green veins. The treatment consists of injecting manganese into the tree trunk (capsules are available from arborist supply stores). But before you take action, do a soil test to ensure the tree is suffering from a lack of manganese.

Sunburn

Japanese maples are highly susceptible to sunburn on the trunks and branches, so be very careful not to prune too many low or interior branches. Removing those branches can expose those areas to the sun, leading to significant damage. Similarly, be careful about pruning trees when your Japanese maple is an understory tree. If you must increase sun exposure, do so slowly throughout at least two seasons. Sudden exposure to the sun will have detrimental effects on your tree.

Watch Now: How to Grow a Crimson Queen Japanese Maple Tree

• Is Japanese maple invasive?

  The tree is not considered as invasive in the United States.

• How can I tell what kind of Japanese maple tree I have?

  Japanese maples are grouped by size and form (weeping, rounded, dwarf, mounding, upright, or cascading), leaf shape (palm-shaped or lacy), and leaf color (red, green, orange, purple, white, and pink, depending on the season) which can give you clues about the kind of tree you have.

• Can the roots of a Japanese maple destroy a foundation?

  Japanese maples have rather compact root systems that are not likely to damage a foundation. Depending on the size of the variety or cultivar, plant larger ones no closer than 10 feet from the house.

From: thespruce