How to Plant, Grow, and Care for Japanese Maple Trees
Japanese maples are wonderful ornamental trees beloved for their compact size and unique color. Gardening expert Madison Moulton explains every aspect of growing, from planting to pruning.
When designing a garden, it’s important not to forget about the backbone of an outdoor space – trees. Unfortunately, as backyards shrink, we don’t all have the space for a sprawling tree fifty feet into the air. That’s where Japanese maple comes in.
This stunning ornamental tree is suitable for small spaces and can be planted in containers. Along with compact size, they are also beloved for their bright colors, especially throughout fall.
If you’re considering adding a Japanese maple to your garden, read on for everything you need to know to keep them happy.
Plant Type Small tree
Species Acer palmatum
Native Area Japan
Exposure Partial shade
Watering Requirements Moderate
Pests & Diseases Scale, borer, Verticillium wilt, anthracnose, and powdery mildew
Soil Type Acidic loam
Bloom Time Spring
What Is It?
The Japanese maple, scientifically known as Acer palmatum, is a small tree grown for its captivating leaf color and compact size. The species is part of the Sapindaceae family (commonly known as soapberries), related to other maples and tropical forest trees like litchis.
The specific epithet palmatum gives a clue in identifying the leaves, derived from the Latin for ‘hand-shaped.’ Each leaf has pointed lobes that spread out and look like your hand’s fingers. But the real attraction of these leaves is their color, turning a range of bright or dramatic shades throughout the year.
Besides their ornamental value, one of the reasons these trees are so popular is variety. There are several subspecies and hundreds of cultivars with different leaf shapes, overall structures, and, most importantly, colors. This, paired with their size, makes them ideal for growing in almost any garden landscape with the right environmental conditions.
While they make wonderful focal points, Japanese maples will work just as well in mixed beds with shorter shrubs. With growth stunted by a restricted root system, they are also suitable for planting in containers long-term and are often trained into bonsai trees by specialized growers.
With so much to love about these ornamental trees, they are a must-have in any moderate-climate garden. As these experience only a few problems, they are ideal for beginner gardeners and won’t require much attention once established.
Japanese maple is, evident in the name, largely native to Japan, with some spilling into Korea and China.
In their natural habitat, these trees form part of the understory layer of forests, growing under the dappled light filtered through taller trees above. They grow in moderate temperatures, preferring cooler conditions over extreme heat.
Luckily, these trees weren’t restricted to their native habitats for long. The expertise of growers has delivered a long list of beautiful cultivars now grown worldwide.
In terms of size, Japanese maples are usually considered small trees. Tiny cultivars may grow to only a few feet, especially if their roots are restricted. Others may be classified as medium-sized trees, but you won’t find any trees growing taller than around 30 feet.
Different cultivars not only come with different sizes but also different structures. Some branches remain upright while others trail down, creating a weeping look. While they don’t strictly need to be pruned year after year, you can also prune strategically to create the shape you want for your landscape.
Once mature, the tree creates a dome of color with plenty of dense leaf growth. They are most appreciated for their color, with the red and orange cultivars particularly popular for the cooler seasons. After this display, these deciduous trees will shed their leaves, growing back the following season.
Even once the leaves have dropped, the delicate branches still provide ornamental interest throughout winter until leaves emerge again in spring. If winter interest is the goal, look for cultivars with interesting bark sporting unique patterns, colors, and textures.
Japanese maples are usually planted in spring or fall, avoiding any temperature extremes to give the roots time to establish. I prefer planting trees in early fall, ensuring they are completely settled in by spring. However, this does mean the roots will need extra winter protection, so it is better to opt for spring planting if you live in an area with chilly fall weather.
Considering location carefully is vital for long-term growth, as these trees stick around long. You don’t want to plant a small tree in the fall only to realize it’s not quite right for the space when it grows. Consider the mature size, environmental needs (and, of course, your garden design) to pick the perfect location.
The ideal spot is morning sun and afternoon shade, well-draining soil with a slightly acidic pH. If you have sandy or poor-quality soil, amend with plenty of compost before planting and continue to mulch with compost throughout the year to improve soil structure.
It’s also best to avoid windy areas, especially when the tree is still young. They don’t typically need staking, but you’ll want to choose a protected site to prevent root and branch damage. Avoid planting close to nearby structures to avoid root problems or interfering branches. Ensure you know your specific cultivar’s mature size to get it right.
After planting, water thoroughly to encourage the roots to establish in their new home. Also, add a layer of mulch around the tree, but not touching the trunk, to retain moisture and suppress weeds.
How to Grow
Your tree’s needs will mostly be met by planting in the right location. They also require more attention in the first few years of growth to establish well. After that, you won’t need to worry much about care at all.
Japanese maples form part of the understory of forests in their native habitats, preferring filtered sunlight or partial shade. However, every cultivar is different, so it’s important to know the requirements of your specific type.
Intense afternoon sun can cause leaf scorch and potentially an unwanted change in the color of the foliage. Deep shade will also cause some types to remain largely green rather than changing color as expected. A balance, preferably by providing full morning sun and some afternoon protection, will deliver the best growth in most varieties.
Some are more tolerant of full sun than others – particularly those with red leaves. If you’re worried about the afternoon sun, choose one of these more tolerant varieties:
- Beni Hime
- Glowing Embers
- Red Flash
- Vandermoss Red
An east-facing position will provide plenty of morning sun to boost growth without risking scorching. You can also plant near a taller tree that may provide shade or on the eastern side of your home, as long as you don’t plant too close to structures.
Proper watering is crucial, especially in the months after planting. To replicate the conditions they experience in their native habitats, they prefer soil that is consistently moist and cool but never waterlogged, allowing air to flow through the soil around the roots.
Watering is most important after planting. It’s best to water every few days to keep the soil moist, encouraging the roots to grow downwards into the soil. Avoid shallow watering – a deep root system will help the tree better manage dry spells and wind. Keep an eye on soil conditions so you can water again when the soil dries out.
Once the tree is established, you won’t need to worry about watering as often. You can stick to watering on a similar schedule to the rest of your garden, only adjusting during dry conditions or periods of sudden heat. Adjust your watering during the rainy season to avoid overwatering and potential root problems.
When planting in containers, care is slightly different. Even if planted in a large container, the soil will dry out much quicker than in the ground. Water every couple of days in pots, keeping a close eye on the soil in summer. Lack of moisture will lead to stress that may stunt growth and affect leaf color.
The ideal soil is slightly acidic loam, retaining enough moisture to keep the roots hydrated while allowing the excess to drain away.
Sandy soil will lead to stress due to lack of moisture, while heavy clay soil will stifle root growth and potentially lead to rot. In either case, the solution is compost. Amend the soil with compost before planting, digging deep down to where the roots will reach before backfilling the hole.
In containers, choose a well-draining potting mix rather than garden soil that is often too dense and carries potential weed seeds or soil-borne pests and diseases. Choose a high-quality mix and top it up with compost as a mulch to maintain good soil structure.
Temperature and Humidity
Japanese maples prefer moderate climates, growing best in USDA zones 5 to 8. They don’t appreciate high temperatures, with the leaves often lacking color in warmer areas. Check the requirements of your specific cultivar to choose the perfect type for your region.
These trees are hardy down to zone 5 but don’t appreciate early frosts or strong winds. Protect young trees from temperature dips with a frost blanket until they are mature enough to handle conditions on their own.
Even if you choose a tough cultivar, trees in containers will need some extra root protection over winter. In containers, the roots are far more exposed to the cold, especially once they’ve grown to fill out the entire container. Cover the pot with a blanket and consider moving the pot to a more protected location if there are unexpected temperature drops.
Japanese maples are not considered heavy feeders and don’t usually require much additional feeding when planted in nutrient-rich soil and when mulched regularly with compost.
If you do want to give them an extra boost, use a low-nitrogen fertilizer in early spring. Don’t fertilize before fall or feed with any fertilizer high in nitrogen, as this will affect leaf color later in the season. Also, avoid applying more fertilizer than needed, as this can stunt root growth.
Since these plants enjoy moist soil, make mulching a regular part of your care routine. Choose an organic mulch that will break down over time to improve soil conditions slowly. Avoid using wood chips as mulch, as this will increase the nitrogen levels in the soil over time, affecting color.
When applying mulch, use a thick layer and keep it away from the tree’s trunk. Soggy mulch sitting against the trunk will lead to rot and can encourage disease.
Japanese maples don’t require much pruning, especially compared to other popular garden trees. If you’re happy with their overall shape, you can leave them to grow without trimming. However, if you want to change the tree’s shape or need to manage growth problems, pruning is an effective solution.
Prune your Japanese maple in late winter if needed (but never in fall), using clean and sharp tools to prevent damage. Remove dead, diseased, or crossing branches to improve overall growth. If you want to lift the tree’s canopy, trim any branches lower down on the trunk. You can also thin the branches to give the tree a more delicate look.
Avoid any heavy pruning, particularly in young trees. Trimming can interrupt growth rather than help it, affecting the eventual shape. Use a light hand, pruning a little more the next season if needed.
It is possible to propagate Japanese maples, filling your garden with these beautiful plants. The process is long, with cuttings only developing into mature trees in several years. However, cuttings will save the day if you have a particular variety you want to replicate and can’t find again.
It’s also possible to propagate from seed. However, the tree you get won’t quite resemble the tree the seed came from. It is an interesting garden experiment, but cuttings deliver much more reliable results in less time.
To propagate from stem cuttings, take cuttings in summer when the branches still have some malleability. Choose a healthy branch with several bright leaves and no signs of damage or disease. Remove the branch from the tip, counting three nodes down.
Dip the cut end in a rooting hormone before planting in a container filled with high-quality potting mix. While rooting hormone is optional, it greatly increases your chances of success, especially in woody cuttings. Decant some of the powder into a separate bowl rather than dipping it directly into the container to avoid contaminating the entire batch.
Once planted, cover the cuttings with a plastic bag, creating a warm, humid environment to encourage root growth. Place the cuttings in a location that receives bright, indirect light and consistent watering to maintain moisture levels.
When the roots have become established and new growth appears, transplant them to a larger container. Continue sizing containers up until the young tree is ready to be moved out into the garden.
Japanese maples encounter very few problems – one of the benefits that make them so popular. However, you may encounter a few stumbling blocks discussed here. If so, apply the relevant fix to ensure your tree thrives in the years to come.
Japanese maples are susceptible to various pests, typically scale insects and borers. These bugs attach themselves to the tree or burrow inside the branches, causing damage to the internal structures and affecting overall health.
To combat these pests, keep up with care to prevent stress and damage, encouraging pests to attack. Encourage predatory bugs in your garden to manage pests for you, and apply a relevant insecticide if the problem does not subside.
Various diseases can also attack Japanese maples: Verticillium wilt, anthracnose, and powdery mildew. Verticillium wilt originates in the soil and infects the tree’s vascular system, leading to wilting and potentially death. Anthracnose causes brown spots on the leaves, and powdery mildew leaves a white, powdery substance covering the foliage.
Using clean tools, pruning to improve air circulation, and the application of fungicides can help manage these diseases.
Discolored leaves can indicate nutrient imbalance (such as high nitrogen) or environmental stressors. Also, look at the light levels and temperatures, as changes in these conditions can cause leaf color to stray from what might be expected.
Regularly inspect your tree for signs of pests and diseases, and consider a soil test to check for nutrient deficiencies if you are sure the environment is not the problem.
Frequently Asked Questions
Can Japanese Maple Trees be Planted in Full Sun?
While some cultivars can tolerate full sun, it is generally best to provide some protection from the harsh afternoon sunlight to prevent leaf scorch. Planting your tree in a location that receives morning sunlight and afternoon shade is recommended for the best possible growth and color.
Will Japanese Maple Grow in Full Shade?
Japanese maple trees are well-suited to shaded locations, originating from forest habitats. They prefer filtered sunlight or partial shade for the best growth but will typically grow fine in full shade if you’re happy to tolerate slower growth and less intense color.
Are Japanese Maple Roots Invasive?
Japanese maple trees do not have invasive root systems. You should consider the mature size of the tree before planting, but their shallow roots aren’t likely to cause serious damage or impact nearby plants dramatically.
Why Do Japanese Maple Leaves Turn Green?
Japanese maple leaves may turn green due to excessive sunlight, nutrient imbalance, or heavy pruning. Ensure your tree is planted in the right location, and watch your fertilizing carefully to avoid affecting color accidentally.
Which Japanese Maple Stays the Smallest?
While most cultivars can be kept small by restricting root growth, these cultivars are naturally compact and don’t take up much space:
It’s easy to see why Japanese maples are so popular, no matter the space you have in your garden. Their ease of care and low-maintenance nature mean you’ll have one less concern facing your backyard garden but will still enjoy the brilliantly-colored leaves in the autumn!