Zucchini Rot - Ask Extension
My Zucchini has a black rot on the end that turns yellow so the zucchini is unable to be harvested/eaten. What is this and how do I prevent this with ...
Knowledgebase
Zucchini Rot #908650
Asked July 06, 2025, 10:45 PM EDT
My Zucchini has a black rot on the end that turns yellow so the zucchini is unable to be harvested/eaten. What is this and how do I prevent this with my new zucchini blossoms? Picture attached.
Le Sueur County Minnesota
Expert Response
Good Morning Marci,
Thank you for contacting the U of M Extension Service.
Please click on the following link all about growing zucchini: https://extension.umn.edu/vegetables/growing-summer-squash-and-zucchini
If you scroll down, there is a section about managing pests, diseases and disorders.
This information states:
- Poor fruit set could be due to not enough pollination. Cold, rainy or cloudy weather can reduce pollination.
We've had a lot of rain days lately. This could be a sign of poor pollination. I would wait until the plant is dry, middle of the day, and prune out the bad fruit. Your plants should produce good fruit as the summer progresses.
Good Luck!
