Blossom end rot
Growing problem A black, sunken patch at the base of tomatoes, peppers and courgettes.
What to look for
A dark, sunken, leathery patch at the flower end of the fruit. It is caused by uneven watering, which stops the plant taking up calcium.
When: July to September.
How to prevent it
- Water evenly and regularly, never letting plants dry out then flooding them.
- Mulch to keep soil moisture steady.
- Use large pots, as small ones dry out quickly.
- Avoid damaging roots by hoeing deeply.
How to deal with it
- Remove affected fruit so the plant puts energy into healthy ones.
- Keep watering steadily, and later fruits are usually fine.
- Adding lime or calcium will not fix it.
Crops it affects
If you choose to use any treatment, use only products approved for UK home gardens, follow the label and avoid spraying open flowers. See all pests and diseases.