Pocket Botanist
Check these first
- Look for small bumps on the twigs or leaf undersides.
- Check if the soil is dry to the touch.
- Observe if the leaves uncurl during the cooler evening hours.
Likely causes
Maple scale
Most likelyHow to tell: You will see small, raised bumps on the twigs or undersides of leaves. These insects suck sap, causing the leaves to curl and lose their vigor.
What to do: Apply a dormant oil spray in early spring to smother the insects. For active infestations, use an insecticidal soap according to the label instructions during the summer months.
Heat and drought stress
PossibleHow to tell: Leaves curl inward during the hottest part of the day to conserve moisture. The edges may turn brown or crispy if the stress continues.
What to do: Provide a deep, thorough watering to ensure the root zone is moist. Apply a 2 to 3 inch layer of wood chip mulch around the base to help retain soil moisture.
Find out what's wrong with your sugar maple
The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.
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When to worry
It is normal for leaves to curl slightly during extreme heat to protect themselves. You should worry if the curling persists into the night or if you see visible pests on the branches.
Stopping it coming back
Keep the tree well watered during dry spells and monitor for scale insects in early spring. A healthy tree is much better at resisting pest damage.
Sugar Maple: curling leaves? Check yours with a photo
Every plant is a little different. Take a photo of your sugar maple and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.
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Questions people ask
- Do Sugar Maples flower?
- Yes, they produce small, greenish yellow flowers in early spring before the leaves emerge. They are not showy but are essential for early pollinators.
- Are curled leaves a sign of Verticillium wilt?
- Verticillium wilt typically causes branch dieback and yellowing rather than just curling. If you see one side of the tree wilting while the other looks fine, consult an arborist.
More problems with Sugar Maple
This article was generated with AI on from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.