Acer palmatum (AY-ser pahl-MAY-tum)is a compact, woody member of the Sapindaceae family of plants.
This perennial, deciduous tree’s genus name, Acer, is Latin and means maple tree. The specific epithet, palmatum, refers to the palm or hand-like shape of the leaves.
As a native of eastern Mongolia, Korea, Japan, China, and southeastern Russia, Japanese Maple has long been used as an ornamental landscape plant in these parts of the world.
During the 1800s, Acer palmatum was distributed to other parts of the world. The first specimen was planted in Britain in 1820.
This small, attractive tree is available in many different forms, including upright and weeping varieties.
All types of Japanese Maple provide great summer and autumn interest thanks to their brightly colored deep green leaves that put on an ever-changing brilliant display as the weather cools.
What are some of the most popular Acer palmatum varieties?
- Crimson Queen has deep red leaves that turn bright reddish-orange in the fall.
- Bloodgood is a variety that produces bright red samaras late in the summertime.
- Beni Otake is Japanese for Red Bamboo. This tall, ornate variety is a wonderful choice for a Japanese garden.
- Butterfly is a lace-leafed variety, making another prettily ornamental choice for a small garden space.
- Sango kaku has a tall, slim vase-shaped growth habit. You may also hear this variety referred to as Coral Bark.
- Inaba-shidare is a very upstanding variety that waves pretty, cascading branches.
- Suminagashi has reddish-purple leaves in the springtime, transitioning to deep burgundy late in the summer.
- Lemon Chiffon‘s leaf colors darken and deepen throughout the summer, creating a variegated effect.
- Shishigashira has crinkly, curled leaves, making it an excellent focal point.
- Tamukeyama is a dramatic choice with billowing, cascading limbs, and deep red bark.
- Dissectum Atropurpureum is a smaller variety that does very well as a specimen plant when planted in a large container.
- Osakazuki‘s deeply lobed leaves start out as a dusky olive green in the springtime and gradually transition to a very bright shade of green by mid-summer. As summer dwindles into autumn, the leaves transition to yellow, bronze, red, tan, and finally brown.
Most Japanese Maple varieties can be counted upon to provide a colorful show; however, performance may vary depending on location and environmental conditions.
- Acer Palmatum Care
- How To Propagate Japanese Maples
- Acer Palmatum Main Pest or Diseases
- Suggested Japanese Maple Uses
Acer Palmatum Care
Planting and Caring Tips for Acer Japanese Maple
Size and Growth
In addition to its attractive color displays, Acer palmatum takes an interesting form. The canopy or crown of young trees spreads broadly and is rather flat on top. It tapers sharply to the trunk. The effect is something of an inverse pyramid shape.
This is very pronounced in young trees. The crown of mature trees tends to fill out and become more rounded with time. As the tree gradually matures, its limbs spread, fill out and take on a lush, layered appearance.
Because this compact Maple can be considered both a tree and a shrub, it is not unusual to find specimens with multiple trunks and a more bush-like growth habit. These plants typically grow at a rate of one or two feet annually.
Generally speaking, Japanese Maple has a slow to moderate growth rate; however, this varies from one variety to another. Some may reach full maturity within 10 years, while others may take as long as thirty years to attain complete growth and maturity.
The maximum height of Acer palmatum varies depending on its environment. It may grow 25’ feet high in its natural setting with an equal spread. Outside its native settings, it will typically top out at 10’ or 15’ feet high.
Flowering and Fragrance
These pretty trees produce clusters of very small, rather insignificant blooms early in the springtime. Flowers may be white or reddish-purple and grow in umbels.
The flowers are pretty and delicate up close. Each individual five-petaled bloom has five red sepals. This creates a pleasant pinkish haze effect when seen from a distance.
In the fall, blooms transition into bright green winged seeds (samaras), which become bright red.
The seeds are also very interesting to look at, fun for imaginative kids to play with, and annoying to deal with as they fly far and wide in search of a place to set down roots.
The leaves of the various types of Acer palmatum are generally hand-shaped, but they may vary in the number of fingers (lobes) represented on each hand. The 2″ to 5″ inches leaves have a minimum of five or a maximum of nine lobes.
All provide a great deal of late summer and autumn color, transitioning from green to yellow to orange, bronze, red, and burgundy. Some varieties have very colorful branches and twigs.
The Best Japanese Maple Varieties – Acer Palmatum
Light and Temperature
These small trees are typically understory trees in their natural environment, so when planting in the landscape, you’ll do best to choose a setting that offers some shelter from the harshest sun and protection from high winds.
In the northern parts of its growing range, Japanese Maple may be able to do well in full sun. Choose a setting that provides morning sun and noonday/afternoon shade in the southern areas of its growing range.
Excessive amounts of harsh, direct sunlight will cause leaf scorch.
Acer palmatum is quite cold-hardy. Most varieties can do very well in USDA hardiness zones 5-7 and tolerate temperatures as low as -13° degrees Fahrenheit.
Watering and Feeding
Keep freshly planted; young trees well-watered until they have become well-established. As with most plants, the soil should be slightly moist, never soggy.
Generally speaking, a very deep weekly watering should suffice.
Established trees should have a regular deep watering schedule throughout the growing season. This is especially true if you live in a scorching area or are experiencing drought.
Extended periods of heat and drought will burn the plant’s roots.
A 3-inch layer of organic mulch surrounding the tree (but not touching the trunk) will help keep the plant’s roots cool while conserving moisture.
Mulch also provides some nutrients slowly and steadily as it decomposes.
Give your Japanese Maple a feeding of a controlled-release or slow-release granular fertilizer very early in the springtime before the leaves appear.
The product you use should have a nitrogen content measuring between 10 and 15. Follow the packaging directions carefully.
Soil and Transplanting
Acer palmatum can do well in a wide variety of soil types; however, as with most plants, it will do best in soil that is light, airy, fertile, well-draining, and able to retain just the right amount of water to keep the roots cool and nourished.
Moreover, sandy loam is ideal.
This plant is not picky about pH levels; however, a slightly acidic soil will encourage better growth. Amend your soil with ample amounts of organic matter, such as pine bark and peat, to achieve these qualities.
How To Plant a Container-Grown Japanese Maple Tree – Don’t Make This Common Mistake
When growing your Japanese Maple as a container plant, a fluffy, slightly acidic mix appropriate for Azaleas will work for your maple tree.
Choose a commercially prepared azalea mix or create your own mix using mostly pine bark with about fifteen percent peat and five percent perlite added.
Grooming and Maintenance
It’s best to prune Japanese Maple trees only minimally. A light trim, late in the winter before the buds open, maybe all the grooming your tree needs to help it maintain an attractive shape throughout the growing season.
Take care just to trim around the edges using a very sharp, sterilized cutting implement. Don’t cut through the main, supportive, structural limbs.
Throughout the growing season, limbs not getting sufficient light will tend to dwindle and fall on their own.
If you notice that a branch is not doing well, or if environmental conditions damage areas of the shrub, of course, you should prune them away carefully as needed.
If your tree has become overgrown and you want to perform heavier pruning, do it in the early summer after the tree is fully leafed out or in the autumn after all the leaves have fallen.
Some lower-growing varieties may need to be staked until they mature. This helps prevent a sprawling growth habit and encourages strong trunk growth.
How To Propagate Japanese Maples
Japanese Maples are very easy to propagate. They grow enthusiastically from seed and can also be grown from cuttings or grafting.
Grow Acer Palmatum From Seeds
Japanese Maple seeds have a very hard outer coating. They need exposure to the elements to germinate. When they fall to the ground, it may take a couple of years for them to germinate.
You can reduce this time to a dependable year by collecting and exposing seeds to artificially generated “elements.”
Follow these 10 steps to hurry Japanese Maple seeds along:
1. When you harvest seeds to plant or store, you should wait for them to ripen and fall in the late autumn. Gather them and break off their wings.
2. Place the seeds in a paper bag and store them in a cool, dry place throughout the winter.
3. Remove them from the bag and place them in a heat-proof container early in the spring (about a hundred days before you plan to plant the seeds).
4. Pour hot water over the seeds and soak them in a warm location for about 24 hours.
5. Place them in a plastic bag filled with a slightly moist mixture of peat and sand. Seal the bag and then poke a few air holes in it.
6. Put the bag in your refrigerator and leave it there for a hundred days. When you remove them from the fridge, it should be late spring/early summer.
7. Plant the seeds outdoors on the surface of a well-prepared bed of well-draining soil. Note that this should be in a shady place.
8. Cover the seeds very lightly with less than an inch of topsoil just to hold them in place.
9. Water gently, deeply, and thoroughly, then allow the soil to dry completely. Water deeply again. Continue with this method through the summer.
10. By fall, you should have a few small seedlings to survive the winter. Mulch around them to protect them during the cold winter months.
Your fittest seedlings will reappear in the coming spring, and you can relocate them as you wish.
You’re not wrong if you believe this sounds like a lot of hard work! Really, these trees grow so happily from seed when left to their own devices that it’s best to leave them to it if you have that option.
Grow Acer Palmatum From Cuttings
To grow Japanese Maple from cuttings, you should take 6″ cuttings late in the springtime or early in the summer. As with most plants grown from cuttings, you should select healthy stems with many leaf nodes.
Plant them immediately into a moist, coarse potting mix. If you cannot pot them up instantly, place them in a water container for a few minutes while you prepare your soil.
Situate your cuttings in a warm, humid, sheltered location where they will receive bright, indirect sunlight.
Keep the soil slightly moist until you begin to see new growth; then, you can transition to a soak-and-dry watering method.
When your cuttings are well-established, transplant or repot them as desired.
Is propagating by grafting Japanese Maple hard to do?
Grafting is a somewhat advanced gardening skill you may not wish to undertake unless you are experienced.
The presenter in this video demonstrates grafting and alternatives for seed and cutting propagation.
Growing Japanese Maples from Seed, Cuttings & Grafting | Spring Update
Acer Palmatum Main Pest or Diseases
Rugged and enthusiastic as it is, Acer palmatum can fall prey to a wide variety of ailments and pests when grown outside its native environment.
One common problem these trees encounter is early springtime damage. This is because, outside of their native setting, these trees tend to leaf out very early and are then damaged by late spring frost.
Insect pests that frequent maple trees include:
- Root Weevils
- Maple Worms
Soil Nematodes can also be troublesome, and soil with very high pH levels can cause maple trees difficulty up-taking iron. This results in problems with chlorosis, which manifests as very early yellowing of leaves.
Other potential problems include viral and fungal infections, such as anthracnose, botrytis, Verticillium wilt, Fusarium wilt, leaf spots, tar spot, and stem cankers.
Drought can cause some problems, such as browning leaves, stems, and limbs. Fungal cankers may also develop on trees that are not getting enough water.
Is the plant considered toxic or poisonous to people, kids, and pets?
Acer palmatum is non-toxic to people and dogs but quite toxic to horses. It is also worth noting that the Red Maple (Acer rubrum) leaves are toxic to people, pets, and livestock.
Generally speaking, it’s a good idea to keep your pets and livestock away from maple trees; however, if you know what you are doing, you can use very young, tender Acer palmatum leaves in a number of Japanese recipes, and they can even be eaten raw. They have a slightly sweet, maple-y taste.
Dried and roasted Acer palmatum samaras (with wings removed) are also edible. They can be munched on as a crunchy snack or ground up and added to flour to add subtle flavor and texture to baked goods. They can also be eaten raw when picked from the tree before falling naturally.
Although the sap of the Japanese Maple is not as sweet as Sugar Maples, it can be gathered and used as a light, natural sweetener. It can also be boiled down to create a more concentrated syrup.
The branches, bark, and leaves of Acer palmatum have several uses in Chinese traditional medicine.
Is the plant considered invasive?
Japanese Maple is a very energetic spreader, and it has easily escaped cultivation almost everywhere it has been introduced.
In Australia and New Zealand, it can be seen growing merrily along the roadsides, lining streams, and springing up in lawns.
It is broadly naturalized in Hawaii, the eastern United States, and Canada. As a result of these plants’ rambling ways, several species are listed as problem plants or invasive in the state of Virginia, Washington DC, and New York State.
Suggested Japanese Maple Uses
This compact, showy, ornamental shrub or small tree has a wide variety of uses in the yard and garden or as a container plant.
Its pretty leaves and often interesting bark make it an enchanting addition to a children’s garden. Many activities and projects can be centered around gathering leaves and samaras and even tapping the tree for sap.
A row of Japanese Maple grown as shrubs can make a dazzling privacy hedge. On the other hand, an individual tree stands out as a specimen plant in a small garden or courtyard setting.
In a natural woodland setting, deer and rabbit-resistant Acer palmatum bring color and interest to the understory.
This pretty plant can be adapted as art when grown as a bonsai in a home, apartment, or office setting.