Blossom end rot on eggplant
A physiological disorder rather than a disease — the result of calcium running short in the growing fruit. Usually it is not a lack of calcium in the soil but uneven watering and growth that is too fast.
Symptoms
- A watery patch at the blossom end of the fruit
- The patch darkening, sinking in and turning leathery
- Dry, brown-black rot with no unpleasant smell
- Symptoms on the fruit only — the leaves stay healthy
- The first fruit on the plant worst affected
What it does to the crop
- Unmarketable fruit that will not keep
- The first and most valuable pickings lost
- Secondary fungal infection where the rot has formed
- Symptoms recurring if watering stays uneven
What encourages it
- Uneven watering — drought alternating with flooding
- High temperature and rapid evaporation in the tunnel
- Too much nitrogen and potassium, blocking calcium uptake
- A salty or very acid growing medium
Prevention
- Water evenly and regularly, ideally by drip
- Mulch to reduce swings in moisture
- Lime the soil to pH 6.0-6.8 before planting
- Avoid excess ammonium nitrogen and potassium
- Foliar feed with calcium while the fruit is setting
⚠️ Before you reach for a spray
This atlas is informational and still growing — different diseases can look almost identical. Confirm the diagnosis and read the product label before applying any plant protection product. If you are unsure, ask your local extension or advisory service.
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