poor fruit set on tomatoes - Ask Extension
What is the max temperature at which tomatoes will still set fruit?
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poor fruit set on tomatoes #916511
Asked September 04, 2025, 6:11 PM EDT
What is the max temperature at which tomatoes will still set fruit?
Lincoln County Oregon
Expert Response
Thanks for the question.
Generally, sustained daytime temperatures over 85 deg F and nighttime temperatures over 70 deg F may stress the tomato plants and change the flowers to a degree that it will be difficult to pollinate them and set fruit.
If you're growing tomatoes in a greenhouse or cloche, ensure you have some means of gauging the inside temperature and providing ventilation to lower the temperature if necessary. A temperature-controlled exhaust fan is one suggestion.
Generally, sustained daytime temperatures over 85 deg F and nighttime temperatures over 70 deg F may stress the tomato plants and change the flowers to a degree that it will be difficult to pollinate them and set fruit.
If you're growing tomatoes in a greenhouse or cloche, ensure you have some means of gauging the inside temperature and providing ventilation to lower the temperature if necessary. A temperature-controlled exhaust fan is one suggestion.
