Should I prune off the curled leaves?

Only prune them if they are dead or heavily infested with pests. Otherwise, leave them as they still help the tree produce energy.

Is curling a sign of walnut blight?

Walnut blight typically causes dark, water soaked spots rather than curling. If you see spots, inspect them closely to distinguish between blight and pest damage.

Why are my English walnut's leaves curling? Causes and fixes

Check these first

Inspect the undersides of leaves for tiny insects.
Check if the curling happens only during the hottest part of the day.
Feel the soil to see if the tree needs a deep watering.

Likely causes

Heat Stress
Most likely
How to tell: Leaves curl inward during the hottest part of the day and may look slightly scorched at the edges. The tree usually recovers once the sun goes down.
What to do: Provide a deep, slow soak of water to ensure the roots are hydrated. Apply a layer of organic mulch around the base to keep the root zone cool.
Aphids
Possible
How to tell: You see small insects on the undersides of the leaves and a sticky substance called honeydew on the foliage. The leaves may curl or pucker as the aphids feed.
What to do: Spray the leaves with a strong stream of water to knock the aphids off. If the infestation is heavy, use an insecticidal soap according to the label instructions.

Curling leaves on other plants

Find out what's wrong with your english walnut

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

Curling is normal during extreme heat waves if the tree recovers at night. Be concerned if the leaves stay curled permanently or show signs of yellowing and spots.

Stopping it coming back

Keep the tree well watered during the summer and monitor for early signs of pests. A healthy, hydrated tree is much better at resisting both heat and insects.

English walnut: curling leaves? Check yours with a photo

Every plant is a little different. Take a photo of your english walnut 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

Should I prune off the curled leaves?: Only prune them if they are dead or heavily infested with pests. Otherwise, leave them as they still help the tree produce energy.
Is curling a sign of walnut blight?: Walnut blight typically causes dark, water soaked spots rather than curling. If you see spots, inspect them closely to distinguish between blight and pest damage.

Guides to these causes

Aphids

Why are my English walnut's leaves curling?