Solar energy is the factor that allows plants to develop. Different plants have adapted to it in different ways.
The Japanese maple needs 6-8 hours of direct sunlight a day. With this sun exposure, you can count on bright leaf color, a dense crown, and vigorous growth.
That was a short answer and we’ll go over it in more detail later on. By the way, be sure to read How to Plant and Care for Japanese Maple Trees.
Generally speaking, it is better for Japanese maple to get direct sun in the morning. In the afternoon, it is better to keep it in the shade.
Depending on the variety and climatic zone, the sun hours should be 6 to 8. In the north, the maple can easily get 8 hours or even more. At the same time, in zone 9, it is better for a Japanese maple to receive no more than 6 hours of direct sunlight.
To be more specific, each variety has different sunlight requirements. You have to study the maple you want to buy and figure out where to put it in your yard.
Some maple varieties will have richer leaves if they get several hours of direct sun. At the same time, in the southern states in full sun all day, these maples can lose their color vividness.
There are popular varieties that can tolerate full sun all day. One such is Emperor 1. This maple has an upward growing habit and bright red or cherry leaves.
Among the green-leaved maples, Mikawa Yatsubusa is the best in full sun. It is a unique variety that has a compact growing habit and very bright green leaves.
Too much sun
Japanese maple is not often damaged by excessive sunlight. In most cases, other factors are responsible for the brown spots on the leaves.
However, there may be times when the sun does cause damage to a maple. This can happen in the extreme heat of zones 8-9.
If your maple gets sunburned, the first thing to do is to water it with a few gallons of water.
Next, place a shade over the tree. You can do this by placing a garden umbrella if the tree is small. For larger specimens, you need to make a frame and put shade netting over it.
Also, be sure to mulch the root zone with a layer of mulch at least 2-3 inches thick.
If sunburn recurs then you need to transplant the maple to a place with some shade.
Newly planted maples are also very susceptible to sun damage. This is due to the fact that their root system is not yet developed and is not able to supply water to the leaves quickly. As a result, the leaf edge turns brown.
To remedy this, make sure to shade the tree in the first year after planting. Water the newly planted Japanese maple as soon as the soil is 1-2 inches dry and mulch it.
Once the young maple is rooted, it will become more resistant to the sun.
Not enough sun
Japanese maples are shade-tolerant trees. In their native environment, they very often grow in the shade of large trees without much trouble.
Therefore, there should be no serious consequences of the Japanese maple not getting direct sun. The crown of such a maple may not be very dense, but overall it will grow normally.
The second is the color of the leaves. In full shade, some varieties may have less bright leaves. This does not apply to green Japanese maples but red or burgundy.
It all depends on the shade over the maple. If it’s growing under the canopy of a tree with a loose crown, so it’s in dappled sun, then it’s OK. In this case, there is enough light for normal leaf color.
On the other hand, if a Japanese maple grows in total shade and gets a minimum of reflected light, this can be a problem.
In this case, the leaves not only may not have their natural color but may also be very light. This often happens if the Japanese maple is grown indoors.
If your maple is growing in the shade, you should definitely make sure that it gets enough reflected light. Otherwise, transplant it to a lighter location.