Why has my dwarf box hedging gone brown
By Keithab
United Kingdom 
I have extesive area of box hedging and certain areas have gone brown and the leaves dropped off. Other areas seem fine with healthy growth
9 Nov, 2008
Answers
If it is box blight you will have to prune out all affected branches and hope that the re-growth is unaffected. If you leave infected branches on the plant the disease will spread further. Look up box blight on RHS website or similar.
10 Nov, 2008
It sounds like either 'Box Blight' or a magnesium/potassium deficiency in the soil. Try feeding with potash.
10 Nov, 2008