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In all seasons, red maple gardeners know what to expect of the red maple. The changes are like clockwork and are so in tune that it’s impossible to miss them.
In the spring, the tree perks up to produce small red flowers that contrast its green leaves. Then summer comes along, and you sit under the tree, enjoying its shade and gazing at its beautiful green foliage.
And in the fall? That’s the best part! The anthocyanins work their magic, creating a gorgeous, red-leafed canopy. Winter finally starts, and the leaves die back, exposing red stems. Magical.
So, seeing your red maple tree’s leaves turning brown can make you wonder where that change fits into the cycle. And the answer is it doesn’t.
The only time the leaves of your red maple should be turning brown is when they have fully aged and gotten to the point of falling off the tree.
The leaves then fall to the ground, decomposing and feeding the tree.
Your Red maple tree may be turning brown for other reasons which is not natural for your tree; getting too much sunlight (sun scorch), not enough water, waterlogging, frost and fertilizer burn.
Thus, if the tree’s leaves are browning to an extent where you’re worried, something is not adding up. The same holds for if the younger leaves are browning – as these are not in the stage of dying and falling off the tree.
What could be the problem, and how can you fix it? Browning issues often relate to sun damage, underwatering, and overfeeding. Are you guilty of any of these? Let’s find out:
Why Is Your Red Maple Turning Brown and How Can You Fix It?
Red, orange, and yellow are the colors you expect the red maple to exhibit in the fall. And in the summer and spring, you look forward to green leaves. So, why would your red maple tree’s leaves be turning brown?
1) Your Tree Is in Too Much Sunlight
The red maple is a hardy tree that can grow in USDA zones 3 to 9. In the lower zones, the tree can do well in full sun and will tolerate partial sun.
But in the higher zones, the case is the opposite – the tree tolerates full sun and does well in partial sun. What do these terms entail?
Full sun refers to light exposure for at least six hours a day. This light should be bright and direct, i.e., unobstructed.
Such exposure allows the tree to use the energy it gets from the photons to trigger enough photosynthesis to make food.
Partial sun relates to at least six hours of light exposure a day. This light should be bright and indirect. Sometimes, people refer to it as filtered light or dappled light. The key here is to reduce the tree’s exposure to too much light.
Usually, a red maple will grow in the full sun, even in the higher USDA zones, without showing signs of distress.
But in the summer, the light exposure comes accompanied by heat, which puts a strain on it.
Rather than make food from the light, the leaves suffer a condition known as leaf scorch, creating burn brown marks on the surface. When this happens, the leaves die and can no longer make food.
Leaf damage owing to too much sun exposure is often coupled with:
- Browning on the leaves on the upper section of the tree (the lower leaves appear seemingly unharmed),
- Crisping of the leaves,
- Wilting, and
- Premature leaf loss.
The latter happens in cases where the damage is extensive.
Can You Save Your Tree?
Once the leaves turn brown, you cannot save them as the cellular damage is final. But you can save the leaves that are yet to suffer a similar fate. How?
If you live in a hot region, your summer will likely be unbearable for the red maple. Thus, when planting the tree, position it towards the east of the garden, where it can receive morning sunlight.
Afternoon rays are unforgiving and can scald the tree’s leaves. People living in cooler climates can position their trees in the south if they live in the northern hemisphere and the north if they live in the southern hemisphere.
These spots receive bright and direct light all day, encouraging the tree to make food. But if the sun is still too much for the red maple, consider moving it to a shaded spot.
Please do the same for indoor red maples by moving them towards east-facing windows.
2) Mulch the base of the tree to reduce the evaporation rates
When doing this, ensure you keep a distance of at least three inches between the tree’s trunk and the mulch. Otherwise, you can create an ideal environment where pests and disease-causing microorganisms can thrive.
3) Keep the tree shaded from harsh winds
Did you know that winds can stress the tree and wick away its moisture? That leaves it exposed to the sun, furthering the foliage damage.
4) Water the tree regularly
Do this to keep up with the increased temperatures. I will detail this in the next section.
5) Be careful when fertilizing
Root damage owing to fertilizer burn can hamper the roots’ ability to absorb water in the summer. I will also cover this in the next section.
It might take a while before you understand how much sun your tree can tolerate. But once you do, the road should be smoother going forward.
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2) Your Tree Needs More Water
Established red maples are highly adaptable trees that can do well in moist and dry soils.
But in the summer and other hot months, leaving them without water only increases their risk of suffering sun damage. A tree that needs more water exhibits the following warning signs:
- The leaves appear droopy,
- Curling of the leaves,
- The leaves become crispy and start browning, and
- The soil appears cracked and feels dry to the touch.
Younger trees are more likely to show such signs, but mature ones can also suffer such a fate.
How To Water the Red Maple
Younger red maples need more water because they are yet to establish their root systems. But once they can reach the water tables, it becomes much easier to care for them. How should you ensure your tree has adequate access to water?
1) Mulch the tree’s base
Use an inch of mulch to reduce the ground’s exposure to the sun and wind. That reduces the loss of water and also helps you control the weeds.
Ensure you keep at least 3 inches of space between the mulch and the tree to encourage air circulation and keep pests at bay.
2) Consider the type of soil you are using for the red maple
Clayey soils have better water retention and thus need less watering. But sandy soils have high water drainage rates and require replenishment at least once a week.
3) Always check the soil before watering it
I advise getting a moisture gauge as it allows you to get better readings and avoid making costly watering mistakes.
Alternatively, you can reach into the top two inches of the soil and assess if they need water.
Only water the soil when it feels dry. And once you do, wait at least 3 days before watering the tree again unless the soil feels dry again (sandy soils dry out fast).
4) Water the tree when the sun is not out
Ideally, you should do this in the late evening or early in the morning to allow the tree to absorb enough moisture. And when watering the tree, do not splash it.
Instead, use a watering can so you can soak the soil slowly so that the roots have time to absorb the water. You can use a watering bag to increase the soaking time.
How much water does your red maple need? You should equate the amount of water to the diameter of the tree’s trunk. For every inch of the trunk, use 10 gallons of water to soak the soil.
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3) Your Tree Has Fertilizer Burn
Your red maple hardly ever needs fertilizer. But most gardeners enjoy replenishing the soil for younger trees to encourage them to grow.
It is also good to feed the tree if it appears malnourished and has poor growth.
However, too much fertilizer can be problematic as it can damage the roots and keep them from taking up water and nutrients. And this leaves the tree exposed to sun damage, pest infestations, and more.
How Should You Feed the Red Maple Tree?
As a rule, you should not feed the tree without testing its soil. You can get a testing kit from your local gardening store. When conducting the test, focus on the major nutrients – nitrogen, phosphorus, and potassium.
Are they enough? If the answer is yes, do not feed your tree. But if the levels are low, you can invest in a commercial feed. Use the fertilizer at half its strength only in the early spring or late winter.
And ensure that you get a slow-release option that will not overwhelm the roots. Most importantly, always adhere to the manufacturer’s instructions.
You can also use compost and other organic feeds that are less likely to harm the tree’s roots. These release nutrients gradually and improve the soil’s texture.
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Did you know that too much sun exposure is often the cause of all browning? The other problems become more glaring when your red maple is in too much sunlight.
For example, if your tree does not have enough water and is in the full sun, it loses more moisture and becomes more dehydrated.
So, start by checking how much light your tree gets and if this is not ideal, fix that, and the rest of the solutions will follow suit.