With a huge range of colors, sizes, and leaf shapes, it’s difficult to get an accurate description of the Japanese Maple, but these attractive trees offer a refined growth habit that make them a welcome asset to your yard or landscape. This tree is known for the finely-cut, lacy leaves, stunning fall coloring, and very delicate structure.
It’s good to note that most horticulturalists refer to any cultivar in Acer palmatum as a Japanese Maple, but it also includes cultivars in A. japonicum. It’s important to note the difference as A. palmatum is hardy in zones six through eight while A. Japonicum is only hardy through zone five. It also has a much more sturdy appearance, and it produces purplish-red flowers in the spring months.
Japanese Maples make nice specimen trees or lawn trees for shade, and there are cultivars that are the perfect size to put in bigger patio containers or in shrub borders. Upright cultivars work well in woodland gardens as understory trees. You can place them wherever you want to add fine texture in your garden, and this quick guide will help you take care of them to ensure that they thrive.
The Japanese Maple is a very striking but slowing growing tree that can add a splash of color and elegance to your yard all year-round.
Japanese Maple History and Cultivation
Japanese Maples have had a critical role in Japanese history for centuries. They were first mentioned during the early seventh century, and they were widely cultivated as early as the 1700s. Over the centuries, they’ve been refined and bred into hundreds of cultivars that are all eye-catching.
Starting in Japan, this tree slowly spread across the globe and reached the West by the time the 1820s rolled around. When you talk about the Japanese Maple, you’re actually referencing nearly two dozen species instead of a single one, and nearly two dozen of them are native to parts of Japan. A. japonicum, A. palmatum, and A. shirasawanum are the three most common cultivars, but you’ll also see A. argutum, A. micranthum, A. rufinerve, and A. tschonoskii all listed as the common Japanese Maple when you shop.
The Japanese also like to deep-fry salted leaves in a sweet batter as a snack in Osaka, but you have to be sure you use freshly picked, young leaves as early in the season as you can or they can make you sick and be very bitter.
The foliage on the Japanese Maple is also renowned. The leaves will offer five to nine palmate lobes, and they can come in red, green, or both colors. During the autumn months, the leaves turn to stunning shades of purple, yellow, red, or orange, and there are many textures present on the leaves. Some have wider lobes while others offer a lacy look. The flowers are smaller and purple or red, and they turn into a dry winged fruit that is roughly a half inch long and called a samara.
Japanese Maple – Quick Guide
|Botanical Name:||Acer palmatum|
|Common Name:||Japanese Maple|
|Flower Coloring:||Purple or red|
|Hardiness Zones:||Five to nine|
|Mature Size:||15 to 25 feet wide and tall, depending on the cultivar|
|Native Zone:||China, Japan, Korea, and parts of Russia and Mongolia|
|Soil pH:||Slightly acidic|
|Soil Type:||Well-drained but moist|
|Sun Exposure:||Part shade to filtered sun|
Choosing the Correct Habitat for Your Cultivar
Before you settle on one type of Japanese Maple, you want to read the tag to determine the best habit for it and find out what size the mature tree will grow to. There are three main types to consider, and they include:
- Dwarf – If you want a smaller tree to put in a big container or in a smaller garden, this is the best cultivar for you. Little Princess or Red Dragon are excellent cultivars that don’t get over five feet tall and eight feet tall respectively.
- Upright – If you’re after a statement piece for your yard, look for a colorful, tall, upright cultivar that is between 10 and 20 feet like Coral Bark, Purple Ghost, or Bloodgood.
- Weeping – A weeping Japanese Maple like Crimson Queen will look nice if you want the tree to perform like a shrub would in the yard. It acts like a decorative feature and takes up horizontal space.
Choosing the Correct Shape for Your Space
Once you pick out the Japanese Maple variety you want in your yard, it’s time to find a space for it. Pull the plant away from any others before you buy it and look at it from every angle. You want to get a shape that works for you. A tree will usually grow into this shape as it matures.
You could prune it to try and direct the final shape, but it’s usually a better idea to pick a tree that you like the shape of when it’s young instead of trying to fix it as it grows. Try to envision what this small tree will look like when it’s fully mature with the same basic structure and shape as it has now but with a bigger trunk and thicker branches. If you like the shape, it’s the correct tree for you.
Not all maple trees are the same shape, so finding one that fits your space is critical to ensuring that you’re happy with the mature tree.
How to Grow Japanese Maple Trees
Generally speaking, Japanese Maple trees are smaller and they’ll fit into virtually any yard. They’re prized for the striking leaves, and they give a lot of visual interest in winter and fall due to the samara and leaf coloring. They make a stunning addition to any landscape design. They do have a reputation for being finicky, but if you plant them in their preferred conditions, they’re not that challenging to keep happy. Japanese Maple trees are slow-growing, so you’ll need patience.
The size of your mature tree will depend on the cultivar, and it can range anywhere from a smaller shrub to a full-grown tree. On average, they top out between 15 to 25 feet wide and high, and they have a vase-like or round shape, but there is also a weeping shape. This tree is prone to issues with scale, pests, borers, and Japanese beetles. Other issues and diseases to keep an eye out for include bark split, scorch, verticillium wilt, tar spot, twig kill, leaf spots, and manganese deficiency.
Along with looking out for these issues, you want to keep the following growing conditions and requirements in mind to ensure you end up with a happy and healthy tree.
Fertilizing your Japanese Maple might not be necessary, and too much can cause issues like reversion and problems with diseases. However, if your tree isn’t looking as healthy as it can be, consider testing your soil. If you don’t want to do a soil test, the best bet is to practice low fertilizing.
Since these trees are slow-growing, too much fertilizer, especially a nitrogen-rich one, can be harmful to the tree. You can get fertilizers that are specially formulated to work on Japanese Maples, but you can also get an all-purpose, controlled-release option. Dig six-inch holes halfway between the trunk and the drip line and apply the fertilizer every few feet as the directions indicate.
Japanese Maples are trees that love shade, but they do require a little sunshine to get the best coloring. You want to put them in a spot that gets morning sun and afternoon shade, or at least dappled shade. The further south you’re trying to grow a Japanese Maple, the more afternoon shade you should give them. Green maples are more sun tolerant than red leaf Japanese maples. However, they are all prone to leaf scorch with too much sun exposure.
Adding a few inches of mulch will help retain moisture around the tree, and it’s also a great way to suppress weeds and help regulate the soil temperature. You don’t want your mulch to be right up against the tree’s base because this will smother it. Instead, layer mulch lightly close to the trunk and put a thicker layer down as you move away from the tree’s trunk.
Japanese maple trees usually leaf very early in the spring, and this is fantastic from an aesthetic purpose. However, late spring frosts could kill the fresh growth if you’re not careful. Any trees you plant in full sun are very prone to late spring frost damage because the areas will warm quicker and encourage earlier leafing. One way to delay this is to add a thicker layer of mulch around the tree’s base that is three to four inches thick.
Many people skip adding mulch to their trees, but this critical step can help regulate the soil temperature to reduce the chances of early leafing and help retain moisture.
This tree loves well-drained but moist soil. Sandy and loamy soil work well for it, but you should avoid a high alkalinity level in the soil. They do well with slightly acidic soil, and they’re not extremely picky about the soil type. However, if you can get 40% fine silt or sand with 40% organic compost and 20% peat moss, your tree will thrive. It gives excellent drainage each time you water with an excellent capacity to hold nutrients. Also, adding 20% peat moss will help boost the acidity level a little and lower the pH.
Temperature and Humidity
Green leaf cultivars of Japanese maples like dry, hot climates. Otherwise, this tree does well in zones six to eight, and some cultivars like zone five. You should protect them from any area that gets strong winds as this can damage the tree.
Even though this tree likes the soil to drain well between watering sessions, you should make a point to water them regularly. The easiest way to regulate the moisture level of the soil around the tree is to add mulch. Until the tree has time to establish itself well, you should water it whenever the soil feels dry, especially if it hasn’t rained a lot.
At the store, this tree can be anything from very cost-effective to extremely expensive, and this is why a lot of people want to propagate them on their own. Also, if you have a tree that does very well in a surrounding yard, you can take a cutting and grow it knowing that it does well in your area.
Not all maple trees will root well using cuttings, but a lot do, so it’s worth a try. During the spring, you want to take softwood cuttings and use a sterile pair of shears. Softwood is usually red or green, depending on the cultivar, and it’s malleable. Hardwood is the wood that hardened and turned brown.
To start, snip the tip of the branch so you have roughly five inches of soft tissue and two leaf nodes. Try to make your cut at a 45° angle and remove any leaves from the lower half of the cutting. Dip the end of your cutting into a rooting hormone before planting them in four-inch containers with a soilless rooting medium. Adding a 50-50 mix of perlite or vermiculite and sand is great. Poke a hole in the center of the soil and insert a cutting.
Gently firm the medium around the base and water lightly to cause the soil to settle. Place a chopstick on either side of the cutting so that it stands an inch or two above it and cover it with a clear plastic. Check your cuttings once a day to make sure your rooting medium stays moist but not soaked. After four weeks, tug gently on the plant. The plant should resist at this point. Once they develop roots, you can replant them after hardening them off.
You can grow this plant from seeds, but you should keep in mind that the new cultivar won’t grow true to type. This means that it may not have the exact same coloring or deeply lobed leaves as the parent tree. Over the summer months, the blossoms turn into samaras. The seed pods have little “wings” that attach to the seed itself, and they spin like a helicopter blade as they fall from the tree to the ground during the late summer and early fall months.
Once you find the seed pods, it’s time to collect them. You should act very fast because once your Japanese maple has pods that start to fall, the whole tree drops the pods in a few days. You can pick the pods up from the ground too, but the pods you pick straight from the tree will germinate best.
You can plant the seeds right in the ground after you pick them or they fall from the tree, but this is inconsistent. It’s a better practice to harvest the seeds, test the viability, and gold stratify them using seed trays. To harvest the seeds, you’ll want to break the wings off and put the seeds in a bowl of room temperature water for 24 hours. At the 24 hour mark, collect the seeds that drop to the bottom of the container. The floating seeds aren’t viable.
If you’re in planting zones four to seven, start the seeds in containers. Fill a seedling flat with a seed-starting medium that you fill to three-quarters of an inch from the top of the tray. Put your seeds in the tray roughly four inches apart and cover them with a quarter inch of soil and lay a piece of hardware cloth or screen over the top. Next, put your flat outside in the cold in a partially shaded area for the winter.
This cold stratifies the seeds in a natural way. You want to keep the soil moist but not wet until they germinate. In the spring months, you should see green sprouts. Remove the cloth and put the flat in a shaded area in your yard.
If you live in zones eight and nine, you’ll have to artificially stratify the seeds. Put the soaked seeds in a bag full of moist sand and force the air out before sealing the bag. Put it in the refrigerator for three months. Check every few weeks to ensure that the sand hasn’t dried out. During the early spring months, put the artificially cold stratified seeds in a flat full of seed starting medium, roughly four inches apart. Adding equal parts coco coir and compost is great.
Put the tray in a window that has indirect but bright sunlight for four hours a day, and keep the potting medium moist. Once the seedlings start to emerge and produce a set of true leaves, you can transplant them into their permanent spot.
One tree can produce a huge amount of seeds, and they’re easy to pluck from the tree before they fall to the ground. This increases your chances of getting viable seeds.
From Seedlings for Transplanting
Planting your transplants starts with the hole. You want to ensure that it’s big enough, and it should be twice as wide as the root ball on the tree and deep enough that the top of the root ball is flush with the soil line once you water it in. A little too high is fine, but you’ll have issues if you go too deep. If the Japanese maple is rootbound, you can make a few cuts with your pruners or a knife to free them.
Backfill the hole really well, and add in some compost material. You want to tamp the soil down to get it to settle around the plant. The trunk should be straight at this point, and if there are grafts, make sure that the graft joint is just over the soil. It’s a good idea to stake the tree temporarily if you live in an area with high winds. Any bare roots should also get staked during the first growing season.
Pruning and Maintenance
To prune your Japanese maple, get a clean pair of shears that you wiped with a cloth dipped in 10 parts water to 1 part bleach. This step will help prevent diseases from spreading. In the middle of winter, before any new growth sprouts, go outside to do the bulk of your pruning. This means you’ll remove any crowded or rubbing branches and shape the tree to your liking. If the tree is overgrown, you can trim it back by up to a third. If you want to shorten branches, trim them back to where the joint of two smaller stems emerge for a clean look.
If you’re trying to remove a full branch, you should trim it to the collar, and this is the shoulder between the trunk and the branch. You can trim away dead or diseased branches at this time, but don’t do major pruning projects in early spring or late winter. This can kickstart growth before the last frost, and this can kill the tree.
There is one exception to consider when you prune with clippers or shears, and this is if you spot reversion. This is common when a grafted plant has cells that cause it to try and revert back to the parent form. If you see leaves forming from the graft that look like they’re from another type of Japanese maple, you want to tear the entire stem or branch off instead of cutting it. This way, you’re more likely to tear away the errant cells, and pruning it will remove the branch beyond a point where it can recover.
If you spot a lot of suckers emerging out of the soil around the tree, you want to snip them off as close to the soil as you possibly can. Do this again when they return. If you don’t catch them quickly, they can spread and the whole tree will revert.
With any luck, you won’t need to prune your Japanese Maple tree, but you should focus more on light pruning versus heavy pruning if you have to do so.
Popular Japanese Maple Cultivars
Finally, there are hundreds of Japanese maple cultivars available in a huge range of colors, sizes, leaf textures, and shapes. A few popular ones include:
- Acer palmatum ‘Coonara Pygmy’: If you’re going to grow your tree in a container, this cultivar is a fantastic choice. It’s a dwarf Japanese maple tree that offers pink leaves in the spring then turns a reddish-orange in the fall months.
- Acer palmatum ‘Sumi nagashi’: This is a slightly faster-growing option when it comes to Japanese maples. It will grow well in zone five.
- Acer palmatum ‘Villa Taranto’: If you’re after a weeping Japanese maple, consider this cultivar. It has very delicate leaves that turn a pretty yellowish-gold in the fall.
- Acer palmatum ‘Wolff’: One of the best Japanese maple species for zone five and zone four is Wolff. It has pretty purple foliage and is called the Emperor I.
You now know the big points to help you take care of your Japanese maple tree. You can use this quick guide to help you choose a tree, find the perfect spot for it, and grow a stunning specimen that will be the highlight of your yard all year-round.