Japanese maples are some of the most fascinating trees in modern horticulture. In this article, you will find solutions to the most common problems associated with Acer palmatum.
QUICK ANSWER: Fungal diseases due to overwatering and high humidity are the main reasons the Japanese maple is dying. Root rot, lack of water, and over-fertilization can also force the Japanese maple to die.
Verticillium Wilt and other diseases
Verticillium Wilt is a disease that has caused the death of many Japanese maples. The pathogens of this disease cause the cambial layer of the tree to die off and it slowly shrinks.
The pathogens can enter the tree in a variety of ways. For example, through open wounds or by using non-sterile pruning tools. Insects can also infect Japanese Maple with the disease.
In the early stages, the disease shows itself as wilting and browning of the leaves. Black areas also appear on the bark. The smaller branches begin to die off.
In the later stage, the top or one side of the Japanese Maple dies off. The branches will shrivel up and turn brown.
How to revive
To avoid the disease, always use only sterile pruning tools. After pruning, treat wounds with an aqueous solution of a multipurpose fungicide. Avoid overwatering the tree and ensure good air exchange around the crown.
If the disease occurs, cut off the infected branches below the damage. Use a sharp and sterile tool.
Read also: Japanese Maple Diseases With Pictures
Root Rot
Root rot is the second most common cause of Japanese maple death. It usually happens because the soil around the roots is too wet, and Japanese maples hate wet feet.
As a result of overwatering, the roots become soft and lack oxygen. This is a perfect environment for the development of rot, which quickly destroys the roots.
Symptoms of root rot are browning or yellowing of the leaves. As a result, the leaves are dying. The second sign is constantly wet soil in the root zone.
How to revive
To avoid root rot, plant Japanese Maple trees away from places with a lot of water, such as a pond, a stream, or a place where water collects from the roof. Use well-drained soil for planting.
Water the Japanese maple only when 2 inches of soil is dry, but not before. Fully established trees need almost no watering.
If root rot occurs, eliminate the cause of overwatering. Water the tree less frequently or move water away from the root zone if possible.
Next spring, the Japanese Maple will be transplanted to a less wet location. Read how to do this properly in the article How to Transplant Japanese Maples?
Not enough water
Lack of water causes very much like dying symptoms in the Japanese Maple. This usually happens during summer heat and drought.
Like all plants, the maple needs water for everyday existence. But when there is not enough water, its leaves begin to wilt. If the sun is powerful at this time, the leaves can turn brown around the edges.
Dehydration is the first thing that causes the leaves to die. At the same time, the tree may go into summer dormancy. To check if the maple is alive, crush one of the buds, if it is green on the inside then the maple is still alive and can be saved.
How to revive
Water the Japanese maple with a few gallons of water so that the soil around the roots becomes moist.
Place shade over the tree, if possible, for a few weeks.
Water the Japanese Maple as soon as the soil is more than 1 to 2 inches dry. Keep an eye on the soil around the root zone at all times. Newly planted and potted maples are most susceptible to dehydration.
Read more: How much water does a Japanese maple need?
Overfertilizing
Very often, people want to speed up the growth rate of the Japanese Maple by giving it a lot of fertilizer. This causes damage to the root system that becomes visible as brown burns on the leaves.
Another possible indicator of overfertilization is fast growth but poor maturation of the leaves and branches. As a result, they become soft and hang down.
How to revive
The first thing to do is to replace the topsoil with fresh soil. But don’t damage the roots. Replace only the soil to the depth where there are still no roots.
Water the Japanese Maple with plenty of water to wash excess salts from the soil.
In the future, Japanese maples will be fertilized no more than once a year with a slow-release fertilizer. Always follow the product manufacturer’s recommendations.
Read also: How often should I fertilize my Japanese maple?
Alkaline soil
Alkaline soil is not a suitable environment for growing Japanese Maples. Most soils are neutral, but there are places with alkaline soils, and if a Japanese maple is planted there, it will eventually die.
The fact is that in alkaline soil, the tree cannot consume the minerals necessary for photosynthesis. As a result, the leaves turn yellow, which is called chlorosis. The tree begins to grow very slowly and dies.
How to revive
Buy a soil pH test kit and use it as directed on the label. If the pH is above 7.0, you need to use an acidifier.
You can find different types of soil acidifiers on the market. These can be either aluminum sulfate or garden sulfur. Use the product according to the manufacturer’s recommendations.
Also, mulch the root zone with compost. It will also acidify the soil a little and make it more nutritious. But avoid volcano mulching, i.e. do not put mulch on the tree trunk.
Read more: What soil does a Japanese maple need?
Too deep planting
Planting too deep can cause the Japanese Maple to stop growing. If nothing is done, it will most likely die.
Very often, beginners plant trees so that the place where the trunk joins the roots is buried in the ground. This is a critical mistake because, as a result, the trunk begins to rot in this place.
This leads to a stoppage of growth and loss of leaves. After a while, the tree will die.
How to revive
Clean the ground near the trunk. Do this gently to avoid damaging the trunk or roots.
Get to where the trunk ends and the roots begin. This is the right level of ground for the Japanese maple. Remove all soil above this level in a circle 2-3 feet in diameter.
Read also: How to Plant Japanese Maples?
Dying after transplanting
Replanting is always a challenge for all plants. This is also true for the Japanese Maple. It can die if you transplant it while it is already foliated or the roots are badly damaged.
You can avoid negative consequences by transplanting early in the spring when the tree is dormant. When the tree wakes up, it slowly adapts to the new conditions, and the transplanting shock will be minimal.
How to revive
If your maple’s leaves turn brown after transplanting, immediately install shade over it. This can be done using a garden umbrella or installing a frame and stretching the shading net.
Next, water the tree with several gallons of water to avoid dehydration. Watch the soil near the roots; don’t let it dry out more than 1 inch.
Read also: How to Avoid Japanese Maple Transplant Shock?
Share This Post
I have a bloodgood that sure looks dead. What can I do. It is about 10 years old and I live in Texas where we had record heat. It is probably planted to close to the brick.
Hi, Michael. Crush one or two buds and if they are green and moist inside then your maple is still alive. Do everything I recommend in this article. If it is planted too close to the brick replant it next spring.
But if the buds inside are dry, the maple is probably dead and there is nothing you can do about it.
hi, I have a Japanese maple plant that is about 10 years old. The leaves are shoveling up and dying and there’s some green bold marks on the trunk. The Sister plant which is planted in my neighbors yard is doing well and looks great. I’m wondering what disease I’m dealing with and what I can do to make the plant healthy again. Any help would be appreciated. So sad to see it suffering. The plant is in Pennsylvania.
Hello Home Tierney,
Green spots on the trunk are lichen. Although this is not a very serious problem I still recommend removing them. Do it very carefully so as not to damage the bark. Use a plastic tool for this purpose.
After the work, spray the trunk and branches with a multi-purpose fungicide to prevent the reappearance of the lichen.
In one of the photos, I see that the bottom of the trunk is buried in mulch or even in the soil. This is most likely the cause of the deformation of the leaves, as trunk rot may be occurring.
Clean the mulch and soil from the bottom of the trunk. Only the roots should be in the soil and the place where the roots and trunk meet should be slightly above ground level.
Let the trunk dry and spray it with a fungicide. In the future, avoid burying the trunk in the mulch even an inch.