Raspberry cane blight is a common disease causing shoots or the whole cane to die back during the summer. The leaves start to shrivel and die. Dark patches can be found just above ground level. The bark cracks and black pinhead sized fruiting bodies develop. A second type of fruiting body is produced on old canes in spring. The affected canes become brittle and may break off at or just above the ground. The spores are spread in the air and by water splash.

The disease usually infects the canes through a wound caused by the cane midge, late frosts or pruning. Affected canes should be cut back to below ground. The fungus can remain in the soil on infected plant debris. To control cane midge spray the plants with a suitable insecticide in early May and again about two weeks later.

The same fungus can cause root rot in strawberries and canker in roses so do not plant these near raspberries or on old raspberry beds without changing the soil.