Will my leaves uncurl?

Yes, if the curling is caused by heat, they will usually flatten out once the temperature drops in the evening. If caused by aphids, the existing leaves may stay distorted but new growth will be healthy once the pests are removed.

Should I cut off the curled leaves?

Only remove them if they are heavily damaged or covered in pests. Otherwise, leave them on so the plant can continue to photosynthesize.

Why are my smooth hydrangea leaves curling? Causes and fixes

Check these first

Inspect the undersides of the curled leaves for aphids.
Feel the soil to see if it is dry an inch down.
Observe if the leaves flatten out once the sun goes down.

Likely causes

Aphids
Most likely
How to tell: You will see small green or black insects clustering on the undersides of leaves or on new growth. The leaves may look distorted or sticky from honeydew.
What to do: Spray the leaves with a strong stream of water to knock the bugs off. If they persist, apply insecticidal soap every 5 to 7 days until they are gone.
Heat Stress
Possible
How to tell: The leaves curl inward during the hottest part of the day to conserve moisture. If they perk back up at night, the plant is just reacting to the sun.
What to do: Apply a 2 to 3 inch layer of mulch around the base to keep roots cool. Ensure you water deeply every 3 to 7 days so the soil stays consistently moist.

Curling leaves on other plants

Find out what's wrong with your smooth hydrangea

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

Worry if the leaves stay curled even at night or if you see significant damage to the plant structure. It is normal for leaves to curl slightly during a heat wave.

Stopping it coming back

Keep the soil consistently moist with mulch and monitor new growth for pests early in the season.

Smooth Hydrangea: curling leaves? Check yours with a photo

Every plant is a little different. Take a photo of your smooth hydrangea 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

Will my leaves uncurl?: Yes, if the curling is caused by heat, they will usually flatten out once the temperature drops in the evening. If caused by aphids, the existing leaves may stay distorted but new growth will be healthy once the pests are removed.
Should I cut off the curled leaves?: Only remove them if they are heavily damaged or covered in pests. Otherwise, leave them on so the plant can continue to photosynthesize.

Guides to these causes

Aphids

Why are my smooth hydrangea leaves curling?