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Maple Tree Diseases: What to Watch for in BC’s Backyards [And How to Save Your Tree]
- Treeline Management
- Apr 21
- 3 min read
If your maple tree’s leaves are curling, spotted, or dropping early, don’t panic—but don’t ignore it either.
Maple trees are known for their fiery fall colour, gorgeous canopies, and hardy nature. But just like any living thing, they’re not invincible. In fact, some of the most common maple tree diseases in BC can sneak in quietly and leave behind a mess of blackened leaves, thinning crowns, or even dead limbs.
Here’s how to spot the warning signs early—and what you can do to protect your maple.
1. Tar Spot: The Cosmetic Culprit
You’ll know it when you see it: small to large coal-black spots (often surrounded by a yellow halo) splattered across your maple’s leaves like ink blots.
What causes it? A fungus called Rhytisma that thrives in damp, humid conditions—especially when infected leaves from the previous season weren’t cleaned up.
Should I worry? Not really. Tar spot is unsightly, but it rarely harms the long-term health of your tree.
What to do: Rake and bag the fallen leaves in fall. Don’t compost them. This breaks the fungus’s life cycle.
2. Anthracnose: When Leaves Shrivel and Drop Early
If your maple’s leaves look water-stained, curl inward, or fall before summer’s over, you might be dealing with anthracnose.
What causes it? A group of fungi that thrive in cool, wet springs.
Should I worry? It can cause premature leaf drop, but healthy trees usually bounce back the next year.
What to do: Prune to increase airflow, avoid overhead watering, and make sure your tree isn’t stressed from drought or poor soil.
3. Powdery Mildew: A Ghostly White Coating
Look closely—your leaves might look like they’ve been dusted with flour.
What causes it? A fungus called Erysiphe, which thrives in hot, humid summers.
Should I worry? It’s mostly cosmetic and more common in dense, shaded areas.
What to do: Improve sunlight exposure, prune back surrounding growth, and water early in the day.
4. Verticillium Wilt: The Silent Killer
If one side of your tree starts dying back, leaves wilt mid-summer, or fall colour comes way too early—this is the one to worry about.
What causes it? A soil-borne fungus (Verticillium) that enters through damaged roots and blocks your tree’s ability to transport water.
Should I worry? Yes. Verticillium Wilt is fatal to many maples and can kill large branches—or the entire tree—over time.
What to do:
Check for brown streaks in freshly cut branches.
Avoid digging or compacting soil near the base.
Consider deep root feeding and consult a certified arborist.
Do not plant another maple in the same spot if the tree dies.
5. Leaf Scorch: Too Much Sun, Too Little Water
Common in Japanese maples, leaf scorch shows up as crispy brown edges and curled leaves—even if your tree isn’t diseased.
What causes it? Intense sun, heatwaves, and drought stress.
Should I worry? Not unless it happens every summer.
What to do: Water deeply, mulch around the base, and consider relocating your tree to a shadier area in the dormant season.
Maple Tree Species: Which Are More Resistant?
Maple Variety | Disease Resistance |
Sugar Maple | Moderate (Susceptible to Wilt) |
Red Maple | Moderate (Tar Spot + Wilt) |
Japanese Maple | Low (Leaf Scorch + Mildew) |
Amur Maple | High |
Norway Maple | Low (Wilt + Tar Spot) |
Freeman Maple | Moderate-High |
How to Keep Your Maple Tree Healthy in BC
Mulch your root zones – especially in summer.
Avoid root damage – no digging or compacting near the base.
Water deeply, not often – especially during heatwaves.
Keep it tidy – rake and remove fallen leaves in fall.
Prune smart – open up the canopy and call in pros for large branches.
At Treeline Hedge Landscaping, we’ve helped hundreds of property owners protect their trees from avoidable decline—and when needed, we’ve safely removed high-risk trees that posed danger to homes, fences, or neighbouring plants.
Whether you need seasonal care, strategic pruning, or expert landscaping support, we’re here to help.
Still not sure what’s affecting your tree? Don’t guess. Our local team can inspect your maple, diagnose the issue, and help you decide whether treatment, pruning, or removal is the right path forward.
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