Leaf spot
Disease Brown or black spots on leaves caused by fungi or bacteria.
What to look for
Round brown, black or purple spots on leaves, sometimes with a yellow halo. Spots merge and leaves drop early. Chocolate spot on broad beans is a related disease.
When: Summer and autumn, in warm, wet weather.
How to prevent it
- Space plants well and avoid wetting the foliage.
- Rotate crops and clear fallen leaves at the end of the season.
- Avoid working among wet plants.
How to deal with it
- Remove affected leaves and bin them.
- Water at the base and mulch to prevent soil splash.
- Feed to keep plants vigorous, as healthy plants cope well.
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.