My Leylandii hedge is turning brown like if it’s dying. Can you tell me what might be wrong it’s about 18 years sowed?
If the whole tree, part of a hedge, turns brown, it is likely to be a root rot.
If patches die, it could be greenflies, or fungus disease, or it could be due to very heavy clipping that allows little or no annual re-growth.
Brown patches may get worse and will not recover, unless adjoining green parts grow in.