Box blight: how to spot, prevent and treat it disease
How do you spot box blight?
The leaves turn brown and drop, and bare patches open up in the hedge. Young shoots carry black streaks and die back. In damp weather white cushions of spores sit on the underside of the leaves. If instead there are webs of silk, green caterpillars with white stripes and leaves eaten in half circles, it is the box tree caterpillar and not this disease.
How do you prevent box blight?
Keep bought plants apart for a month before planting them, because the products used at the nursery only hold the disease back and do not destroy it. Clip less often, so the hedge does not close up and air can move through. Shape the top rounded and clip only in dry weather. Disinfect the tools between one part of the garden and the next. Do not water over the foliage, and mulch the soil under the bushes so that rain does not splash.
What works against box blight?
In dry weather dig out and remove badly affected plants, and on a treasured one cut out the affected parts. Pick up the fallen leaves under the bush and take off the top layer of soil. Put what you remove into a bag and not onto the compost. The most reliable way is to replace box with another plant for the hedge or the topiary.
Which plant gets box blight? 1
Ornamentals 1
Sources: Royal Horticultural Society
Checked on 18 August 2026.