I have two small box hedges in terracotta pots that are cone shaped. approx 2ft tall, problem is, one of them is starting to discolour a sort of brown pigment. can you help me to sove the problem please.
They need feeding during the growing season but sick plants should not be fed until they show signs of fresh healthy growth.
It is possible they have got box blight but drying out is the more common problem and it can happen in winter too.