The root system is the key to a healthy tree. The soil that surrounds the roots directly affects their quality.
The best soil for Japanese maple is loose and nutritious soil. It is also important that the substrate is well-drained and slightly acidic. To get such a soil mix, add 1-2 buckets of soil conditioner to the native soil.
In the following, I will go into more detail about the soils favored by Japanese maples. Also, be sure to check out the Acer Palmatum Care Guide.
In general, Japanese Maple is capable of adapting to a wide range of soils. So in most cases, you don’t need to do anything to your soil.
But if you want to give your maple a good start, it is a good idea to improve the native soil. The best material for improvement is organic matter.
You can use soil conditioner, compost, or peat. All of these materials work equally well as long as they are of good quality.
Dig a planting hole two to three times larger than the maple’s root system. Mix the soil you got out with 1 bag of organic matter.
Then plant the maple using this mix. Use the rest of the mix to plant other plants as it is a universal substrate and suitable for many other purposes.
The newly planted maple will find it much easier to develop a root system in the improved soil. In addition, organic matter will give it nutrients.
After 1-2 years, the roots will occupy the entire improved soil. Then they will begin to penetrate into the native soil, but you do not need to do anything about it.
Clay is not a good growing medium for Japanese Maple. This is because this type of soil is too long able to hold water and as we know Japanese maples do not like wet feet.
Clay soils are very common on the planet. If you have loam or something similar, you’re fine. But if you have pure clay in your yard, it needs to be improved.
You can do this with the same organic matter. This process is described in more detail in the previous chapter.
Additionally, you can make drainage to avoid wet feet. To do this, when planting the maple, dig a planting hole three times deeper than the root ball and fill it one-third with stones. Then plant the maple there.
Also, avoid planting Japanese maple near the house or other buildings. This is to prevent water from the roof from getting to the roots.
It is also not a good idea to plant the tree very close to a pond or stream. Otherwise, it can get root rot.
Sandy soil is a little better for Japanese maple because it is quickly drained. As a result, the maple will not suffer from excessive water around the roots.
The sandy loam and other types of soils containing sand are well suited for growing this species of maple. There is no need to improve such soil.
Another thing is if you have pure sand in your yard. In this case, you need to prepare a different substrate for planting.
Use black soil or other garden soil that is available in your area. Add a few bags to the place where the maple will grow and mix it with the sand. You can also add some organic matter there.
You should end up with draining soil that does not dry out too quickly. In other words, the soil should hold some moisture, but the water should not stagnate there.
Also, mulch the surface around the maple with pine bark or wood chips. This will reduce the speed at which the ground dries out. A layer of mulch should be at least 2 inches.
Regarding soil pH, the Japanese maple is a tree that likes slightly acidic soil. This means that the optimal range is 5.5-7.0.
Most soils on our planet are neutral, i.e. their pH is somewhere between 6.0-7.0. In this case, you don’t have to worry about anything as your maple will thrive in this type of soil.
But if you suspect that your soil is not suitable. For example, because other trees don’t grow well there, you need to measure the acidity of the soil.
To do this buy a soil test kit. Such kits are widely available on the market.
If the soil is too alkaline (pH>7.0) nitrogen problems can occur. This will cause the leaves to turn yellow. To fix this add a little acidifier such as aluminum sulfate which is also commercially available.
Soil that is too acidic (pH<5.0) is also a problem because it blocks the plants from getting phosphorus. To remedy this, add peat or some garden sulfur to the soil before planting.