Time to act:
Jun, Jul, Aug, Dec, Jan, Feb, Sep, Oct, Nov
Caused by the same fungus responsible for tomato blight, potato blight causes the leaves to develop dark patches, starting at the edges. In humid conditions a white fungus appears around the marks. The infection then travels down the plant to the tubers, which turn a reddish-brown and, if a secondary infection strikes, the crop turns slimy and rots.
Here are organic and chemical ways of dealing with the problem.
Find it on