Pocket Botanist
Check these first
- Feel the soil to see if it is dry.
- Check the undersides of curled leaves for aphids.
- Observe if the leaves recover after the sun goes down.
Likely causes
Heat Stress
Most likelyHow to tell: Leaves curl inward during the hottest part of the day to conserve water, but they should perk up by evening.
What to do: Water the plant deeply at the base during the early morning. If the heat is extreme, provide a light shade cloth during the afternoon hours.
Aphid Infestation
Most likelyHow to tell: Leaves become puckered, yellowed, or curled due to aphids feeding on the sap underneath.
What to do: Wash the leaves with a gentle spray of water. Use neem oil or insecticidal soap if the curling continues after cleaning.
Find out what's wrong with your winter squash
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.
Scan with your phone's camera to get the app
Or go to pocketbotanist.app/get on your phone
When to worry
If leaves stay curled even at night or show signs of yellowing and spotting, the plant is in trouble. Temporary curling during a hot afternoon is normal behavior.
Stopping it coming back
Keep the soil consistently moist and monitor for pests weekly to stop them before they cause damage.
Winter Squash: curling leaves? Check yours with a photo
Every plant is a little different. Take a photo of your winter squash 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.
Scan with your phone's camera to get the app
Or go to pocketbotanist.app/get on your phone
Get the app · Or check it from a photo now, free
Questions people ask
- Is curling always a disease?
- No, it is often just a reaction to heat. Check for bugs before assuming it is a disease.
- Should I prune curled leaves?
- Only if they are heavily infested with pests or turning brown. Otherwise, leave them to provide energy to the plant.
Guides to these causes
More problems with Winter Squash
- Why is my winter squash plant drooping suddenly?
- What are these white spots on my winter squash leaves?
- Why are the leaves on my winter squash turning yellow?
- Why are there bugs on my winter squash?
- Why are my winter squash leaves getting brown tips?
- Why are my winter squash leaves falling off?
- Why is my winter squash not producing flowers?
- How do I fix root rot in my winter squash?
- Why is my winter squash plant growing so leggy?
Back to the Winter Squash guide
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.