Tree · Sapindaceae
Japanese Maple
Acer palmatum
Give it dappled shade, steady moisture, and shelter from wind, and the Japanese maple unfurls color from spring through fall.
Partial shade
Every 3–7 days
USDA 5–8
10–25 ft · 3–7.6 m
Overview
The Japanese maple is a small, slow-growing understory tree, and its palmate leaves are the whole story, each one split into slender pointed lobes that spread open like a hand. Two broad shapes divide the species. Upright forms carry those leaves on rounded little trees, while laceleaf forms mound and weep, their blades cut so deeply and finely that the whole leaf frays into lace.
Color plays across the foliage all season. The palmate leaves run through red, green, bronze, and purple, and in fall they burn to red, yellow, and gold before they drop. The reddish April flowers are so small and quiet they nearly vanish against the leaves, so the tree speaks through its foliage, not its bloom.
It wants patience and a sheltered spot, since hot afternoon sun, drying wind, and dry soil brown and curl the delicate leaf edges. The care that keeps every leaf whole is dappled shade, even moisture, and a thick collar of mulch. Given that, its finely made canopy holds for decades with very little fuss.
Care
The short version: set it in dappled or afternoon shade out of drying wind, keep the soil evenly moist and well drained, mulch the root zone, and prune only in late fall to winter.
Light
The finely cut leaves color best in dappled or afternoon shade, the filtered light this understory tree would find beneath taller trees in the wild. Full sun works in cooler climates, but in hot, dry, windy spots it browns the delicate leaf edges. Deep full shade drains the red and purple to a flat green and lets the form go loose.
Water
The soil stays consistently moist, and more so in heat, since this tree wilts quickly under drought. A 3 to 4 inches (8 to 10 cm) layer of mulch under the canopy holds that moisture in and keeps the roots cool. When the moisture swings under full sun, the thin leaf edges crisp and brown.
Soil
The roots want moist, rich, well drained loam that runs slightly acidic and holds plenty of organic matter. In high-pH ground the leaves yellow between their green veins, a mottling called chlorosis, so acidic soil keeps each blade a clean, even color.
Temperature
The bare wood is hardy across a wide range, roughly -20°F to 95°F (-29°C to 35°C). Late frost, though, can blacken the tender new spring leaves, one more reason to keep it sheltered from the open and the wind.
Humidity
Ordinary outdoor humidity suits it, so there is no number to chase. Even soil moisture and shelter from wind matter far more, since it is dry wind, not dry air, that crisps and curls the fine leaf edges.
Feeding
The tree feeds once in spring before the leaves break, on a slow-release or balanced fertilizer. A light hand is best, since too much pushes weak, fast growth and can raise the salt enough to scorch brown along the leaf margins.
Pruning
Pruning stays sparing and falls in late fall to mid winter, when the tree is bare and only dead or crossing branches come off. Cut into the leafed-out wood in spring or summer and it bleeds sap heavily, so timing matters more here than with most trees.
Repotting
A potted or bonsai specimen is repotted every 2 to 3 years, its mix refreshed and its roots trimmed. Roots circling the pot, water running straight through, and leaves that scorch and stall all show the tree has outgrown its container.
Size & spacing
Left to grow, it reaches 10 to 25 feet (3 to 7.5 m) tall and spreads about as wide, its branches layering out into a broad, low crown. It grows slowly, so it takes years to fill that frame, which makes it easy to place.
When to plant
This tree leafs out slowly and bleeds sap if it is cut at the wrong time. Plant it in spring or fall while the weather is mild, watch the tiny reddish flowers open and fade against the young leaves in April, and hold any pruning for the bare, dormant stretch from late fall into winter.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring or fall, in dappled shade sheltered from drying wind and late frost.
- Harvest: Inconspicuous reddish flowers in April; brilliant fall foliage color (red, yellow, bronze, purple).
Hardiness
USDA hardiness zones: 5–8
Temperature: down to -29°C
Troubleshooting
Trouble reads first in the leaves of a Japanese maple, in the color and edge of each blade, whether a baking site or a hidden root fault is behind it. Look closely and the early marks tell you which one it is. Match what you see below, then act while the fix still holds.
Faded, wilting limbs dying back down one side
When the leaves on scattered branches drain to a dull green, then yellow and brown, and whole limbs sag and die back on one side, the cause is usually verticillium wilt, a soil fungus that clogs the wood's inner channels. Peel back the bark and dark streaks may run through the pale wood, but the pattern mimics fusarium, so a lab culture is the only certain read. There is no cure, so the dead wood comes out, steady water and feed push what growth is left, and no susceptible tree returns to that soil.
Fix:
- No cure exists; prune out dead branches and have a certified arborist assess hazardous dieback
- Support the tree with appropriate irrigation and slow-release fertilizer to encourage new growth
- Remove severely affected trees; plant only resistant species in infested soil
Sticky shoots dotted with soft insects or waxy bumps
A tacky, glistening film on the shoots and small raised specks on the wood give away two sap feeders. Aphids cluster soft and pear-shaped over the tender new growth, while scale cling to the bark as hard, waxy bumps, and the honeydew both leave behind blackens into a soot-like mold. A hard jet of water or insecticidal soap sweeps the aphids away, dormant oil smothers the scale, and a careful eye through the season keeps the bark and shoots clean.
Fix:
- Hose off aphids with a strong stream of water or treat with insecticidal soap/horticultural oil
- Apply dormant horticultural oil for scale and prune out heavily infested branches
- Conserve natural predators and monitor through the growing season
Brown, brittle edges curling in on the leaves
The dry, papery brown that creeps along the margins and tips, curling each leaf inward, is leaf scorch. It marks the leaves most open to sun, heat, and wind while the soil dries beneath them, and it darkens through hot, dry weather even as the roots stay firm and sound. Deep, even watering, a 3 to 4 inch blanket of mulch, and the cool of afternoon shade or a windbreak let the next flush of leaves come in whole and unblemished.
Fix:
- Water deeply and consistently to keep soil evenly moist
- Apply 3-4 inches of mulch beneath the canopy to cool roots and retain moisture
- Provide afternoon shade or relocate to a site protected from sun and wind
Toxicity
Good news for pet owners: the Japanese maple is not toxic to cats, dogs, horses, or other animals. Its thin, lobed leaves carry none of the wilted-leaf danger linked to red maple in horses. A pet that chews a mouthful may get a mild stomachache from the bulk alone, so steering them off the foliage is still worthwhile.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
The thin, lobed leaves hold no poison for a cat, so a curious bite off the low branches does no harm. Should a cat strip and swallow a mouthful, the worst is a coughed-up wad of green or a passing stomachache.
Dogs None
Nothing in the palmate leaves, the smooth bark, or the small winged seeds is toxic to a dog. A big, greedy mouthful may leave the stomach grumbling for a day, the same as any leafy plant.
Horses None
Horses can crop the foliage without harm. These green and red leaves lack the wilted-leaf danger that makes red maple deadly to equine red blood cells, so the tree stands as a safe planting near a paddock.
Rabbits Safe
The finely cut leaves are not poisonous to rabbits in any part. As with any fresh green, they go down best introduced slowly and in small amounts.
Livestock Safe
Cattle, goats, and sheep can browse the leafy growth without harm. Unlike red maple, this tree carries none of the blood damage that worries owners of grazing animals.
Birds Safe
The tree is harmless to birds, which pick at the paired winged seeds and tuck in among the slender branches without trouble.
People Safe
The leaves and sap are not poisonous to people and even see occasional use in cooking and tea. Still, the tree earns its place through the look of its foliage rather than the table.
Generally non-toxic, but any plant material can cause mild stomach upset if eaten in quantity; discourage pets from chewing foliage.
Varieties
Hundreds of Japanese maple cultivars exist, sorted mostly by the shape and cut of the leaf and the habit of the tree. The ones below, from broad palmate lobes to thread-fine laceleaf, are the ones you will meet most at the nursery.
Bloodgood
An upright cultivar whose deep reddish-purple palmate leaves keep their dark, saturated color well into summer, when many other reds have already faded to green.
Crimson Queen
A weeping, mounded laceleaf form whose red leaves are cut so fine and thread-thin that they pour over one another like water spilling from a fountain.
Sango-Kaku (Coral Bark)
An upright tree whose leaves turn a soft, clear yellow in fall, and once they drop, the young bark takes over, burning to its most vivid coral-red through the winter months.
Seiryu
A rare upright laceleaf that holds cool green all summer through its finely dissected leaves, then shifts to gold and red in fall, a departure from the usual weeping threadleaf forms.
var. dissectum / subsp. matsumurae
The threadleaf and laceleaf group as a whole, marked by leaves cut so deeply and finely that they feathery out across a low, weeping mound.
How to propagate
Japanese maples are slow and exacting to multiply, and the named cultivars, with their exact leaf color and cut, will not come true from seed. How you propagate depends on whether you want that precise foliage or simply the species.
GraftingDemanding
Late winter to early spring (bench grafting onto seedling rootstock). · Several months to a year for the graft union to take and grow on.
The named cultivars, with their particular leaf color and cut, do not come true from seed, so the nursery trade holds those traits by grafting. A slip of scion wood is bench grafted onto Acer palmatum seedling rootstock in late winter to early spring, and the fresh union takes several months to a year to knit fast and grow on. The work is demanding, and it is the reliable route to a tree whose foliage matches its parent exactly.
SeedModerate
Sow stratified seed in fall or early spring. · Seedlings establish over one to several seasons.
Seed suits the straight species, though each young leaf emerges a little different and will not repeat a named parent's exact color and shape. Stratified seed sown in fall or early spring settles the seedlings in over one to several seasons. The winged seeds scatter and self-sow so readily that the tree is listed as invasive in Virginia and DC, so collect or contain them where that matters.
Stem cuttingsDemanding
Early summer (softwood cuttings). · Weeks to months to root, with low success rates.
Soft, green early-summer shoots can be struck as softwood cuttings, but the stems are stubborn to root and the success rate stays low. Even the ones that catch can take anywhere from weeks to months to send out roots, which makes the method chancy for most cultivars. Grafting remains the steadier route to a faithful copy.
Myths
Japanese maple leaves are dangerously poisonous to dogs and cats.
Acer palmatum is absent from the ASPCA toxic-plant lists, and like the other maples they assess, its slim, lobed leaves are non-toxic to cats and dogs. The wilted-leaf danger people recall belongs to red maple in horses, a different tree and a different animal. The leaves are safe to plant where pets roam.
Japanese maples must be grown in deep, full shade.
As understory trees they hold their finest color in dappled light or afternoon shade, but heavy shade drains the red and purple to a washed-out green and slackens the branching. The real threat in sun is not the light but scorch, which browns the leaf edges on hot, dry, windy sites where the soil dries out. Filtered light with steady moisture keeps the foliage richest.