Growing Plants

Maple Tree Leaves Turning Brown In Summer: Why? Do I Need To Concern?

Most common trees’ leaves usually turn brown in autumn or winter. However, you can see maple tree leaves turning brown in summer conditions. And you should know that it is abnormal.

So, why are my maple tree leaves turning brown? I will give you some common reasons that cause brown maple leaves and some tips to take care of the trees.

Causes Make Maple Tree Leaves Turning Brown In Summer

maple tree leaves turning brown in summer

There are some main non-disease causes making leaves on maple trees turn brown, relating to some factors such as leaf scorch, drought, too much water, being iron deficient, overfeeding, root damage, girdling, and non-hardy zone.

I will explain more in below:

Scorched Leaves

This issue arises when water from the leaves evaporates too rapidly and cannot be replenished. The dramatic increase in average summertime temperatures is the primary cause of this fast drainage.

The brown leaves on the maple trees dry out appearance because the outer margins burn in the scorching summer conditions.

The remaining parts of the leaves will become yellow, then drain more, and become brown. Finally, dead leaves fall off.

Many circumstances, such as harsh winds and damaged plant roots, also contribute to this phenomenon.

It is not as destructive as direct heat from the sun’s shine, but strong wind damage causes scorched maple brown leaves.

Like in the case of extreme heat, water in brown leaves can evaporate rapidly under dry winds.

And if the roots are injured, the water can not be transferred to the brown leaves. The entire leaves eventually dry out due to a lack of moisture replacement after evaporation.


Leaves in summer on Japanese maple trees turning brown may become brown because they turn yellow or brown under high temperatures in broader summer months.

Large, healthy trees can usually withstand the late summer heat since there are four seasons each year.

However, prolonged sun exposure to the habitat’s extreme temperature will cause the soil and plant moisture to evaporate constantly.

As a result, over a considerable amount of time, the Japanese maple leaves will likewise wither, change color, and eventually fall off.

But some maple trees, like the sugar maple, can endure this high temperature for extended periods.

Therefore, if you are in such a harsh climate, you can consider choosing this species or similar maple tree types for cultivation.

Extreme Water

In contrast to the preceding two explanations, excessive water may also cause Japanese maple leaves to turn brown on maple trees.

The environment or people can play a role in bringing this cause. Gardeners tend to use improper watering methods on their plants during the hot summer months.

In addition, the complicated interplay between temperature and humidity is linked to heavy summer rain.

If that happens frequently, the roots will be destroyed, and water can not be moved from the roots to the stems or browning leaves of the tree.

Deficient in Iron

To plant healthy plants, you must realize that iron is important in nurturing them. As a result, leaf discoloration occurs in the absence of iron.

The green leaves might become white or brown, depending on the severity. Determine whether or not your soil’s pH level indicates an iron deficiency. It is costly when you want to add iron to fertilizers.


Leaves turning brown on maple trees may happen if they get too much nitrogen, potentially leading to other issues.

In fertile soil, mature trees can obtain the nutrients and water they need independently, so excessive fertilizer is unnecessary.

However, fertilizer your plant as directed on the packaging if more nutrients are needed.

Root Damage

Damage roots caused by grower’s digging, illness, fungus, or insects may restrict water to leaves. Therefore, it can pose an even greater threat to young plants.

Small, circular holes around the maple tree base or its trunk indicate root rot. Sawdust may be seen on the ground underneath the tree trunk should things go very bad.


When the bark is stripped away, there is no way for water to reach the dry leaves and trigger the brown leaves on a maple tree.

Water and nutrients cannot reach other plant sections, leading to eventual plant death.

Large shears, animal foraging, and other human interventions are the reasons for this phenomenon.

Non-Hardy Zone

When maple trees are grown for a long period or purchased from a low-temperature area, the browning of leaves happens due to the change of environment.

Therefore, choose those that thrive in the weather conditions typical to your region. Saving time, money, and energy on taking care of trees is possible with careful selection.

So, tree vendors and other experts should be consulted.

What Types of Fungus Can Lead To Brown Leave On Maple Trees?

browning leaves on maple tree

Besides the mentioned causes, fungus infections can cause browning of leaves. There are some types, such as anthracnose fungus, tar spot, and verticillium wilt.

Anthracnose Fungus

Many varieties of maple foliage are susceptible to Japanese maple anthracnose. The leaves will get distorted and curled, ultimately turning brown and falling off prematurely.

The fungal disease is easily transmitted by air currents or water droplets landing on infected leaves or branches.

When the condition progresses, it is not possible to treat it alone on your own. The tree’s leaves will get severely damaged, and the illness will rapidly spread if left untreated.

This illness is caused by fungi, manifesting as sores beneath the leaves that swiftly spread. So, if you see the warning signals, do what you need to stop the problem from worsening.

The plant should be watered, but you should be cautious not to soak the leaves. Leaves infected by fungi should be removed and destroyed correctly immediately.

Tar Spot

Another fungus that might bring up a similar effect is tar spot. Small, circular spots will emerge on the foliage, and the leaves will fall off early.

Aside from the cosmetic damage to the leaves, the disease poses litter danger to plants and has no lasting effect on otherwise healthy perennials.

However, a fungal infection that persists over time can diminish your garden’s therapeutic value.

The best way to prevent this fungus from returning next growing season is to scrape the infected leaves and then burn them.

Another method is to compost the leaves at around 140℉ because this can kill all cells of tar spot. Make sure that the compost is evenly rotated.

Verticillium Wilt

Verticillium, in contrast to the fungus mentioned above, may cause harm to the whole plant, not only the leaves.

This fungus’s invading cells prevent water and nutrients from reaching the entire tree, including the leaves. 

The incubation time for this illness is quite lengthy, and its symptoms are subtle. Falling leaves are only the beginning; the whole branch will lose its vigor and appear like a dry patch.

Furthermore, no fungicide now available can get rid of verticillium. If the diseased plant is still young, it should be uprooted and the solid treated before anything else is planted there.

If the tree is mature and strong, you may help it by providing more nutrients to fight against it.

The soil may be dried in the sun, which is the treatment method because dangerous organisms like bacteria, fungi, and even certain insects may be killed by sun exposure.

The addition of water is why drying is also crucial.

Tips For Caring Japanese Maple Tree Leave

why is my maple tree leaves turning brown

Here are some of my tips for you to plant a healthy maple tree:

  • Ensure that you choose a well-drained and moisture-solid place to plant the tree, which can be exposed to sunshine.
  • Proper watering is necessary in broader summer months.
  • The best time to prune this type of tree is late winter or spring. Other months can be hard for immature plants to grow and prevent severe diseases.
  • Fertilization is essential, but you should not abuse it.
  • Protect your plant from the effects of wind, extremely hot sunshine, or prolonged high heat to limit rapid evaporation.


All in all, in bright summer, maple tree leaves turning brown in summer is caused by environmental factors such as high temperature, strong wind damage, extreme water, excessive fertilizer, etc., and some fungus diseases like anthracnose, tar spot, and verticillium wilt.

In some cases, you don’t need to do too much to prevent this phenomenon, but in others, maple leaves turning brown can indicate severe problems.


Samuel Mark

Hello I am Samuel. Samuel's Garden is a garden blog where I share my experiences in garden caring and tree growth. Hope you enjoy it!

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