Fungal disease
Potato Early Blight
A fungal disease that causes brown target-like spots on older potato leaves.
Symptoms
- Dark brown spots with rings, like a target, on older lower leaves
- Yellowing around the spots
- Lower leaves dying back first
What causes it
The fungus survives in soil and plant debris and attacks stressed or older leaves in warm, humid weather.
What you can do
- Remove affected lower leaves.
- Mulch to stop soil splashing onto the leaves.
- Water the soil, not the leaves, and water in the morning so any splashes dry quickly.
- Do not grow the same crop in the same spot next year; rotate beds for two to three years.
- Feed plants well; stressed plants are more susceptible.
Not sure it's early blight?
Photograph one affected leaf and Plantulus will suggest the most likely problem, with a confidence score. It's free and needs no sign-up.
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General guidance only, not a diagnosis. Check product labels and local rules before using any treatment, and ask a horticultural specialist if a valuable plant is struggling. See the disclaimer.