Knowledgebase

Tomato rotten end #940452

Asked July 24, 2026, 6:32 PM EDT

Can you identify the cause of this tomato plant rot?

Carver County Minnesota

Expert Response

It's called blossom end rot. It is very common.

It is a disorder caused by the plant unable to take up calcium. There are multiple reasons for that, many of which you cannot control. These include inconsistent watering, temperature, variety and root damage. Potted tomatoes are quite susceptible. The first set of tomatoes are most likely to be affected. Read here:
https://extension.umn.edu/garden-problems/tomato-disorders
and here:
https://hort.extension.wisc.edu/articles/blossom-end-rot/
and here:
https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/environmental/blossom-end-rot/blossom-end-rot-of-tomato-and-pepper

Dennis in St. Louis Park Replied July 25, 2026, 3:01 PM EDT

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