Japanese Maple Tree Care: Planting and Growing Tips
The jaw-dropping elegance of the Japanese maple’s vibrant colors and graceful appearance has inspired Japanese poets and artists for centuries. In Japan, the annual pilgrimage to view the tree’s stunning autumn colors (called momiji-gari, or “maple tree viewing”) is an event with spiritual significance.
Although they’re most well known for their fall foliage, richly colored leaves emerge in spring and remain, often evolving throughout the growing season.
What Is a Japanese Maple Tree?
A Japanese maple tree is an ornamental tree that belongs primarily to the species Acer palmatum. There are hundreds of varieties of Japanese maples of varying sizes, forms, leaf types and colors.
There are weeping varieties with cascading branches, upright varieties with branches that grow out and up to heights of 35 feet and dwarf varieties that may only grow from two to eight feet tall. Some have broad fanning leaves, while others have small and delicate leaves with a lacy texture. And they produce a small, colorful fruit (called samara) in the spring.
The leaf colors include purple, pink, red, orange, yellow, green and multi-colored (variegated). Red-leafed Japanese maples (like the “bloodgood”) are among the most common. They produce pink leaves in early spring that turn purplish-red in the summer and culminate in a deep crimson red in fall.
Where Do Japanese Maples Thrive?
Generally, Japanese maples thrive in areas where the average minimum temperature remains above -10 degrees F (USDA Plant Hardiness Zone 6), but some can tolerate temperatures as low as -30 F (Zone 4). Most prefer part sun with afternoon shade because their delicate leaves are prone to scorching. In hotter climates, a Japanese maple may prefer partial or dappled shade. However, some — particularly green-leaf varieties — can tolerate full sun, even in hot climates.
Strong winds can damage fragile branches and dry out the leaves, causing a condition called windburn, especially when combined with hot temperatures. Japanese maples should be placed where they are protected from wind, like the leeward side of your house.
How to Plant a Japanese Maple
Japanese maples prefer loose, well-draining, moist, slightly acidic soil. Fall (one to two months before the first freeze) is the best time for planting, so the roots can get established while the rest of the tree is dormant. Spring planting is also possible after the last frost. Planting in an eastern location that receives morning sun and afternoon shade is best.
Japanese maples can be planted in the ground or in containers. When planting in the ground, place them in a hole that’s three times the width of the root ball and backfill with well-draining soil. For containers, place the tree in a pot that’s two or three times the size of the root ball, and fill with a slightly acidic potting soil mix. Only plant smaller, dwarf varieties of Japanese maple in containers.
How to Care for a Japanese Maple
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Water. After planting, water twice a week for the first three or four months to firmly establish the roots. Afterward, water whenever the soil feels dry, usually once per week. Trees planted in containers need to be checked and watered more often. A reduced watering schedule during autumn will stimulate more vibrant leaf colors.
- Mulch. Apply a two- to four-inch layer of mulch around the tree’s base for moisture retention and root insulation. Maintain a six-inch distance from the base of the tree, and replace the mulch if there is discoloration or decomposition.
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Fertilizer. Japanese maples should only be fertilized after they’re a year old, or during the second growing season. The best time to fertilize is late winter or early spring. Japanese maples are naturally slow-growing trees, so stimulating rapid growth with a high-nitrogen fertilizer should be avoided. Use a slow-release fertilizer instead.
- Frost Protection. Japanese maples leaf out in early spring and are susceptible to freezing and dying during a hard frost. If freezing temperatures are expected, move a potted tree inside and cover outdoor trees with a tarp, burlap or frost protection cover.
How to Prune a Japanese Maple Tree
Japanese maples don’t require much pruning, but periodic pruning can promote the health and aesthetics of the tree.
Perform heavy, structural pruning while the tree is dormant during late winter or early spring. Light pruning and removal of dead or damaged branches can be done any time of year.
Prune a Japanese maple with bypass pruning shears or a pole pruner, following these steps:
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Remove branches that are rubbing against each other.
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Trim back branches that are closer than two inches apart to allow wind to pass through and prevent branches breaking from wind strain.
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Remove dead branches.
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Remove branches growing straight up on trees with a weeping profile.
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Remove branches growing inward, toward the trunk.
- Trim back or remove branches that detract from the desired shape and balance of the tree.
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How to Propagate a Japanese Maple
Japanese maple trees can be propagated from softwood cuttings that will be ready to transplant after about a year. Begin the propagation process in spring after the last frost, once the first leaves have formed, or in early summer.
- Fill a nursery pot with a mixture of half perlite and half peat moss. Moisten thoroughly with water.
- Firmly press the mixture down until it’s partially compacted, and form a four-inch deep hole in the center.
- Cut a six- to eight-inch-long section, 1/4-in. diameter. Section off the tip of the maple tree, just below a spot where a leaf meets the stem (AKA leaf node), at a 45-degree angle.
- Pull off the lower leaves to expose the nodes.
- Soak the cut end and leaf nodes in a mid-strength rooting hormone for about a minute.
- Place the cut end into the hole you formed in the nursery pot with the leaf nodes just below the surface of the potting mixture. Gently compact the mixture around the stem and drizzle water around the base of the cutting.
- Place the pot on a heat mat in an outdoor area with indirect sunlight.
- Mist the cutting twice a day. Only add water to the potting mixture when the top two inches are dry.
- After five or six weeks, check for root development by gently tugging on the cutting and feeling for resistance.
- Transfer to a one-gallon pot filled with potting soil after the roots have formed.
- Continue growing indoors while watering regularly until spring.
- After the last frost in spring, transplant the cuttings outdoors after acclimating them by setting the pot in a partly shaded outdoor location for about a week.
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