Quick Scoop

Blossom end rot on tomatoes is usually caused by inconsistent watering and calcium uptake problems, not a contagious disease, and the damaged fruit will not recover.

How to fix it

  1. Remove the affected tomatoes so the plant puts energy into healthy fruit.
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  2. Water deeply and consistently; tomatoes generally need about 1 to 2 inches of water per week, and the soil should not swing from very dry to very wet.
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  3. Add mulch to help keep soil moisture even.
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  4. Avoid heavy nitrogen fertilizer, which can push fast leafy growth and make calcium uptake less reliable.
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  5. Use a soil test before adding lime or gypsum, since extra calcium only helps if the soil or pH problem is actually part of the issue.
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What not to do

  • Don’t expect eggshells to fix it quickly; they break down too slowly to help current fruit.
    • [3]
  • Don’t rely on Epsom salt, since it adds magnesium rather than calcium and can make the imbalance worse.
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  • Don’t treat it like a fungus or spreadable infection; fungicides and insecticides do not control blossom end rot.
    • [5]

Fast prevention plan

For the rest of the season, keep watering steady, mulch the bed, and use only moderate fertilizer. If you want an emergency option, some extension guidance recommends a calcium chloride spray for new growth, but it still must be paired with corrected watering.

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Bottom line

You cannot save fruit that already has blossom end rot, but you can usually stop it from showing up on the next tomatoes by fixing moisture stress and avoiding fertilizer mistakes. New fruit can come in clean once conditions are steadier.

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