Blossom End Rot
A sunken, leathery, tan to black patch on the bottom of the fruit, on the end away from the stem. It is not catching and nothing is rotting it. The fruit could not get calcium while it was sizing up because the soil moisture swung between soaked and dry.
Disease checklist
Four things to look for. If most of them match what you are holding, you are in the right place.
What gets rid of it
Gentlest option first. For most backyard cases the first one is enough, so try these in order and stop as soon as it works. If you do spray something, the product label tells you how — please read the notice further down.
1Water evenly
Give the bed a deep soak on a schedule so the soil never swings from soaked to bone dry, especially while fruit is sizing.
drip irrigation timerTry this first2Mulch the bed
Two to three inches of straw or shredded leaves holds soil moisture steady between waterings.
straw mulch garden bale3Skip the calcium spray
Calcium sprays on leaves and fruit do not work. Calcium will not move out of a leaf into a fruit, and fruit skin cannot absorb it.
4Do not add calcium blind
Most gardens already have plenty. Get a soil test first, because if the soil calcium is adequate then eggshells, lime and gypsum change nothing.
soil test kit lab5Go easy on nitrogen
Heavy nitrogen pushes leafy growth that competes with developing fruit for the calcium that is moving.
6Protect the roots
Do not hoe deep or cultivate close to the stem. Damaged roots cannot keep water moving into the fruit.
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Which plants get blossom end rot
Every plant we cover that gets blossom end rot, grouped by type — tap any one to open its page. A note beside a plant came from that plant’s own entry, because the same disease can be a minor nuisance on one plant and a serious problem on another. Plenty of plants we do not cover get it too.
Plant families hit hardest
Related plants often share the same problems, so if one plant in a family has it, check the others. The largest group here is Cucurbitaceae, with 3 of the 6 affected plants.
- Cucurbitaceae3 plants
- Solanaceae3 plants
When to treat
Fix the watering the day the first fruit shows it; that fruit will not recover but the next ones can come through clean.
Timing only — the label is the law
This page tells you when to watch for blossom end rot and when treating is worth considering. It is not a recommendation to apply any particular product. Read and follow the product label before you spray — under federal law the label is the legal instruction, and using a pesticide against it is illegal.
- Check the pre-harvest interval. Every product that’s cleared for an edible crop sets a minimum number of days between spraying and picking. Find it on the label before you spray anything you intend to eat.
- Check the re-entry interval before you or anyone else works in the treated area again, and use the protective equipment the label names.
- Confirm the product is registered for your crop in your state. This page groups many different crops together, and a product legal on one of them is not legal on all of them — state registrations differ too. Your state pesticide agency or local extension office can confirm both.
- Rates and mixing instructions come from the label, never from us. We don’t publish them because they differ by product and formulation.
Other problems on the same plants
If a plant gets blossom end rot, these are the problems it most often gets as well, so they are worth checking for while you are out there. They tend to appear together; one does not cause another.