Miscanthus blight

Symptoms

On ornamental Miscanthus (and related grasses), reddish-brown spots and oval streaks develop on the leaf blades and sheaths, mostly on older leaves first. The spots enlarge and run together so leaf margins and tips turn brown and die back, and in bad years the whole clump can look scorched. Young, soft plants can be killed outright. The blight worsens in warm, wet, late-summer weather.