Are curled leaves a sign of Emerald Ash Borer?

Not directly, but EAB causes canopy thinning and branch death which can make the tree look sickly. Check for D shaped exit holes on the bark.

Should I prune curled leaves?

You do not need to prune them unless they are infested with pests. The tree needs its leaves to produce energy.

Why are my White Ash leaves curling? Causes and fixes

Check these first

Look for tiny insects under the leaves.
Check if the leaves uncurl at night.
Feel the soil to see if the tree is thirsty.

Likely causes

Aphids
Most likely
How to tell: You see tiny insects on the undersides of leaves and a sticky substance called honeydew on the foliage. The leaves look puckered or curled.
What to do: Spray the leaves with a strong stream of water to knock the aphids off. Use insecticidal soap if the infestation is heavy.
Heat Stress
Possible
How to tell: Leaves curl inward during the hottest part of the day to conserve moisture. The tree looks better in the morning or evening.
What to do: Water the tree deeply during dry spells to ensure the roots stay moist. Apply a layer of mulch to keep the root zone cool.

Curling leaves on other plants

Find out what's wrong with your white ash

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.

When to worry

If the curling is accompanied by heavy leaf drop or branch dieback, it could indicate a serious issue like Emerald Ash Borer. Minor curling on a few leaves during a heatwave is normal.

Stopping it coming back

Keep the tree healthy with consistent deep watering and monitor for early signs of pests.

White Ash: curling leaves? Check yours with a photo

Every plant is a little different. Take a photo of your white ash 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

Are curled leaves a sign of Emerald Ash Borer?: Not directly, but EAB causes canopy thinning and branch death which can make the tree look sickly. Check for D shaped exit holes on the bark.
Should I prune curled leaves?: You do not need to prune them unless they are infested with pests. The tree needs its leaves to produce energy.

Guides to these causes

Aphids

Why are my White Ash leaves curling?

Check these first

Not sure what's wrong with your white ash?