Troubleshooting
Delicata Squash problems — and how to fix them
Delicata Squash (Cucurbita pepo 'Delicata') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Powdery mildew
Very common late in the season. Choose resistant varieties, space plants 90 cm (3 ft) apart, and apply a dilute baking soda or potassium bicarbonate spray at first sign.
Squash vine borer
Moth larvae tunnel into the base of vines, causing sudden wilting. In the US, cover young plants with row fabric until female flowers open. Remove larvae if found and bury affected stem section to encourage re-rooting.
Poor fruit set
Usually caused by lack of pollinators or poor timing of male/female flowers. Hand-pollinate female flowers (identified by the tiny fruit at the base) with a paintbrush or male flower in the morning.
Prevent delicata squash problems before they start
Most delicata squash issues are care-mismatch, not bad luck. Dial in the basics:
- Common squash problems — the species this cultivar belongs to
- Common delicata squash problems — our other guide for the same plant
- What's wrong with my plant? — the diagnosis apps compared
- Delicata Squash watering schedule
- Delicata Squash light requirements
- Best soil mix for delicata squash
- Delicata Squash temperature & humidity
- Full delicata squash care guide
Looking for delicata squash in general rather than its problems? Read the full delicata squash care guide — light, water, soil and feeding.
Delicata Squash problems — FAQ
Why is my delicata squash powdery mildew?
Very common late in the season. Choose resistant varieties, space plants 90 cm (3 ft) apart, and apply a dilute baking soda or potassium bicarbonate spray at first sign.
Why is my delicata squash squash vine borer?
Moth larvae tunnel into the base of vines, causing sudden wilting. In the US, cover young plants with row fabric until female flowers open. Remove larvae if found and bury affected stem section to encourage re-rooting.
Why is my delicata squash poor fruit set?
Usually caused by lack of pollinators or poor timing of male/female flowers. Hand-pollinate female flowers (identified by the tiny fruit at the base) with a paintbrush or male flower in the morning.