Why Are the Leaves on My Maple Tree Turning Brown in Summer?

There's something unsettling about looking at your maple tree in July and seeing brown, crispy leaves when they should be lush green.

The good news: most causes of summer browning in maple trees are treatable. The bad news: some require quick action to prevent permanent damage.

Here's how to diagnose what's happening to your maple tree — and what to do about it.

The 7 Most Common Causes of Brown Maple Leaves in Summer

1. Leaf Scorch (Most Common)

Symptoms: Brown, crispy edges on leaves while the center remains green. Usually appears on the side facing the sun or wind.

Cause: Utah's combination of intense sun, low humidity, and dry winds causes leaves to lose water faster than roots can supply it. Most common July-August when temps exceed 95°F.

Treatment: Deep watering 2-3 times per week during dry spells. Apply 2-4 inches of organic mulch around the base. Trees in exposed locations may need wind breaks.

2. Drought Stress

Symptoms: Leaves turn uniformly brown or yellow, starting from the top of the canopy downward. Leaves may curl, wilt, or drop early.

Treatment: Maples need 1-2 inches of water per week during summer. Water deeply (slow drip for 30-60 minutes) rather than frequent shallow watering.

3. Iron Chlorosis (Utah Alkaline Soil)

Symptoms: Leaves turn yellow with green veins, then brown at the edges. New growth affected first.

Cause: Utah's alkaline soil (pH 7.5-8.5) makes iron unavailable to maple trees. Norway maples are particularly susceptible.

Treatment: Apply chelated iron fertilizer in spring and fall. Foliar iron sprays provide faster relief.

For healthier soil, check out our lawn aeration guide.

4. Fungal Diseases

Tar Spot: Black tar-like spots on leaves that turn yellow and drop early. Rake fallen leaves in fall to break the cycle.

Anthracnose: Irregular brown patches along leaf veins. Common after wet springs. Most trees recover without treatment.

Verticillium Wilt: Sudden wilting of individual branches with brown streaks under bark. This is serious. No chemical cure exists. Call an arborist.

5. Pest Infestations

Spider Mites: Fine webbing on leaf undersides, stippled yellow-brown appearance. Common during hot, dry summers. Treat with water spray or insecticidal soap.

Aphids: Curled, distorted leaves coated with sticky honeydew. Neem oil or insecticidal soap for heavy infestations.

6. Salt Damage

Brown leaf edges on the side facing the street. Utah's winter de-icing salts accumulate in soil. Deep watering in spring helps flush salts.

7. Overwatering

Yellow-brown leaves in constantly wet soil. Let top 2-3 inches dry between waterings.

See our mulching benefits for your yard guide for how mulch protects maple roots.

Maple Species Susceptibility in Utah

Bigtooth maple (native) — most heat/drought tolerant. Autumn Blaze maple — best non-native choice. Avoid silver maple and Norway maple which are prone to problems in Utah.

When to Call a Professional

Call an arborist if: large branches over 2 inches are dying, more than 40% of the canopy is affected, you see brown streaks under the bark, or the tree has been declining for more than one season.

For cost comparisons on tree care, see our tree removal cost guide in Murray Utah.

Frequently Asked Questions

Should I remove brown leaves from my maple tree? No — let them fall naturally. Do rake fallen leaves in fall to prevent disease.

Can a maple tree recover from leaf scorch? Yes. Scorched leaves won't green up, but new growth will be normal if stress is addressed.

What is the best maple tree for Utah? Bigtooth maple (native) or Autumn Blaze maple.

How much water does a maple tree need in Utah summer? 1-2 inches per week. Deep water 30-60 minutes at the drip line, 2-3 times per week.