Japanese Maple Care – Learn How To Grow A Japanese Maple Tree
The following are some facts about Japanese maples:
1) They have been cultivated since ancient times.
There are over 100 species of maples, but only five or six species are grown commercially today. These include the Eastern White, Eastern Red, American Beech and Western Yellow. All these trees produce cones during their growing season (spring through fall).
Each cone contains seeds which mature into new trees when they’re ripe.
2) Most of the world’s commercial production occurs in Japan, where there are over 200 varieties of maples.
The largest producer is the Kiyomizu Mausoleum, which grows over 300 different types of maples.
3) The most common type of tree used for lumber is the Eastern White.
The wood is light, strong and easy to work with. However, it does not last as long as other woods. It takes several years before the wood begins to lose its strength and durability.
4) Trees grown in Japan are usually raised in pots rather than being cut down from a stand or trellis.
Many begin as cuttings, but are eventually planted into containers where they can continue to grow for five or six years.
5) It takes about 10-15 years before the trees reach a harvestable size.
Most of the large Japanese maples in North America are overgrown shrubs that have been growing for decades.
6) The largest known Japanese maple is located at Aratani Ten Square Garden in Los Angeles at 15 meters tall and 12.
5 meters wide. It’s the largest known of its kind in North America.
7) The wood from the Japanese maple is used for furniture, flooring, veneer and plywood.
8) One of the oldest varieties of maples is the Bloodgood, which was grown in North America since 1699.
It produces the best timber out of all the different types of maples.
9) The leaves of the Japanese maple change their color in the fall, giving a spectacular display of reds and oranges that can last for weeks at a time.
10) The leaves are between three and eight inches long, with three being the most common. They are shaped like lances or arrows, with pointed tips and wavy edges.
11) The structure and branching pattern of the tree is called “ramification”. This is how the tree is judged on whether or not it is a good bonsai tree.
12) Most maples prefer a slightly acidic soil, although there are some that do just fine in basic (alkaline) soils. All of them prefer well-drained soil and dislike water-logged roots.
Planting Your New Japanese Maple Tree
If you have purchased a bare root tree, the first thing you need to do is to plant it. Follow these steps carefully, as the health and ultimate success of your tree may depend on this advice.
1) Before you plant, check the roots to make sure none are damaged or broken.
2) If you’re planting in the fall, begin digging your hole a few weeks before.
This will give the ground time to dry out a bit. If you’re planting in the spring, do this step a few weeks before as well.
3) Clear away the soil from a hole that is twice as wide as your root ball and the same depth.
4) Carefully remove the tree from its pot, taking care not to break the roots.
5) Fill the bottom of the hole with rocks (this will help with drainage).
6) Set the tree in the center of the hole.
If there are any low or damaged roots, trim them off now.
7) Fill in the hole with soil and gently pack it around the roots.
8) Water it well to remove any air pockets in the soil and let it drain.
Watering Your Tree
The next step in caring for your tree is knowing when and how to water it. Japanese maples can tolerate drought conditions, but will not thrive under these conditions. They need regular watering to perform their best.
Your tree should be watered whenever the soil becomes dry on the surface. Check it with your finger. If water is needed, dig a hole about 8″ deep and 12″ in diameter.
If the soil is damp or wet, don’t water.
In the summer, water once per week and in the winter, water only when the soil is dry. Also take care not to over water your tree as this can cause root rot and ultimately kill your tree.
Fertilizing Your Tree
Your maple tree will need nitrogen, phosphorous and potassium. Any general-purpose fertilizer will do (such as 10-10-10). Follow the instructions on the package for how much to apply.
If you’re feeling adventurous, you can try making your own fertilizer for your tree. A recipe is available here.
The goal of pruning is to keep your tree short and wide. This will allow sunlight to reach all the branches and give your tree a natural looking appearance. Heavy pruning is not recommended, as it can injure your tree.
Light pruning every year is all that should be necessary. If you haven’t done so already, I highly recommend reading this link on maintaining the formal bonsai shape. It applies to Japanese maples as well.
Insects and Disease
Japanese maples are prone to a few different insects and diseases. Scale is one that attacks many types of trees and is recognizable by a waxy looking cover on the stems. Spider mites can be a problem as well and are recognized by webbing on the undersides of the leaves.
If you find either of these insects, your best bet is to immediately spray your tree with neem oil. This is an all-natural way to ward off insects and is available in most garden centers.
If your tree develops any diseases or fungus, you can try clearing it with milk. Put a cup of milk in a bucket of water (enough to cover your tree) and let it soak for 24 hours. If the problem persists, you can try again with a different milk (whole, skim, condensed, etc).
I’ve found that whole milk works the best, but don’t use it on trees with soft wood (such as birch or cherry).
Scale: These pests are small insects that look like small bumps on the stems or leaves. They come in different colors and protect themselves with a waxy cover. Most common is the brown, waxy cover.
If you find these, you should immediately spray your tree with neem oil.
Spider Mites: These are very tiny spiders that generally attack trees that are weakened by other factors. Look for webbing on the undersides of the leaves. If you find it, try spraying it with a mixture of half water and half cooking oil.
Cover all the leaves, but be sure to give it at least a day before checking to make sure it worked.
Powdery Mildew: This is usually brought on by an already weak tree or one with too much shade. It is a white powdery substance that appears on the leaves and eventually kills the tree. As with most diseases, the best way to deal with it is to prune the infected branches and try to give it more light.
You can also mix a solution of water and vinegar and spray the tree.
Insects In General: Finding insects on your trees is not a good sign, especially if you see lots of them. This can mean a few different things, but the most common is that your tree is dying. Of course, insects can attack healthy trees if they get enough of a population going and they’re hungry, so don’t necessarily write your tree off just yet.
If you do nothing else, prune the infested branches. Then, you can try spraying it with a mixture of water and a little sugar to sweeten the deal.
Two-Striped Podded Beetle: This is a bug that you’ll find primarily on maples but will occasionally attack other types of trees. They’re hard to kill and only respond to two things: heat and movement. If you have a lot of trees in your yard, it’s going to be too much trouble to try and heat your whole yard (in fact, doing so could be illegal and considered cruel).
Instead, get yourself a “tickled by nature” brand bird scare. These devices do nothing more than move slowly and make noise when the wind blows. This is enough to scare the beetles away but not enough to bother other birds that wouldn’t be eating your trees anyway.
You can pick one up at most garden centers for around $30. They have a timer that shuts it off at night so you don’t have to remember to turn it off.
Leaf Curl: Primarily attacks apple trees. Mainly found on the edges of leaves, these brown and/or black spots will eventually eat their way inward until the leaf falls off. This disease is nearly always fatal to the tree.
There are no cures or really even preventative measures. It spreads by insects, primarily the plum curculio, so keep an eye out for them on your trees and get rid of them immediately.
Cores: Primarily attacks crabapples but can affect other types of trees as well. There are two types of insects that cause this: the apple maggot and flatheaded wood borers. The adult flies look exactly like apples and confuse people into picking them and eating them or even just feeding them to livestock.
Once inside the tree, they lay their eggs and the process begins all over again.
You can generally tell which trees are infected because you will start to see brown sections on the edges of leaves that look like they were attacked by insects. These sections will turn brown and fall off, often just before or after harvest. Once you’ve identified this problem, it’s usually too late for that year.
There are a few preventative measures you can take, but not many. For the apple maggot, you can pick off and destroy any apples that are below average in size and rotting inside. For flatheaded wood borer, you can apply a treatment of sulfuryl fluoride.
It’s a contact poison, so any part of the tree that is covered will be killed. This means that any part of the tree that you don’t want to die needs to be covered somehow. Possible ways to do this include: wrapping the tree with a garbage bag (tape it securely in place), draping the tree with cloth (staple it in place), or smothering it in paint or wax (this method takes forever).
For this to work, you need to do it before the insects have laid their eggs and again after the larvae have hatched. If you think you’ve missed the season, then you can also prune the tree back hard (killing the insects in the process) and hope for the best next year.
Other: There are other things out there but these are by far the most common. Most trees will react to an unexpected change in environment by dropping leaves. It’s only when the tree is consistently dropping more than half of its leaves that it’s a problem to be concerned about.
You are going to have to learn through experience and this will vary from tree to tree. The key is to be observant and keep track of what’s going on throughout the year.
For example, my apple trees always drop a lot of leaves in the spring after they bloom. It’s a lot of extra work for me, but it’s a natural process and the tree always recovers. My pear tree, on the other hand, dropped most of its leaves for no apparent reason and didn’t bloom at all last year.
It needed more water than the others so I’m giving it extra this year with help it along. Now, if this was an orange tree then dropping all its leaves every fall would be normal, but it’s not. It’s dropping leaves all year round!
It looks really sick and weak. I’m thinking it might be Eutypa or some other fungal disease due to the brown spots that are forming all over. I’m not going to bother with any preventative measures this year because it’s probably too late for that and I don’t want to waste my time and money on something that isn’t going to work.
It’s either going to make it or it’s not.
I’ll keep you posted on the outcome.
As always, I hope this has been helpful.
Sources & references used in this article:
Assessment of the maple aphid colony by the hover fly,Episyrphus balteatus (de Geer) (Diptera: Syrphidae) I by E Kan, M Sasakawa – Journal of Ethology, 1986 – Springer
Effects of elevated CO2 and temperature‐grown red and sugar maple on gypsy moth performance by P Gregory, JD Vertrees – 2010 – Timber Press
Trees for urban planting: diversity uniformity, and common sense by RS Williams, RJ Norby, DE Lincoln – Global Change Biology, 2000 – Wiley Online Library
The red maple paradox by FS Santamour Jr – … Book: Cultivating connections with trees, 2004 – books.google.com