Any hedge requires a commitment to regular maintenance.
Regular light trimming of a hedge is better for the hedge, and is easier to carry out, than infrequent heavy pruning.
A leylandii hedge has to be trimmed once or twice a year. All other hedges should be trimmed at least once a year. We do not recommend trimming hedges more than twice a year as it can weaken them, especially if you keep them very tightly trimmed back. We trim our hedges once a year in early summer back to the same width as the previous year. Sometimes we trim the tops (but not the sides) of the Leylandi hedges again in late summer or autumn. Modern power tools do the job quickly and easily when the hedge is trimmed regularly and we have succesfully maintained a leylandii hedge at a height of 120cm (4 feet) for 20 years by trimming it once or twice a year.
If a leylandii hedge is left untrimmed, it will grow up to 90cm (3 feet) a year, may need costly specialist equipment or professional help to get it back into shape and will create large amounts of garden waste to dispose of. Leylandii hedges will not produce new shoots from old wood and cannot be cut back hard once they have become seriously overgrown. For this reason, a leylandii hedge should be well-maintained from the start. If you keep a Leylandii hedge at a height of 6-7ft tall, it is easy to trim. If you let your hedge get taller than this, you will need specialist ladders or platforms to trim your hedge safely.
Never cut a leylandii hedge back so hard that you are cutting into old wood (branches with no green shoots on) as they will not re-shoot.
If the boundary is shared with a neighbour, they should be consulted, as they will need to maintain their side of the hedge. You should ensure they have the ability to do so and you should not allow the hedge to grow to a height where it becomes a nuisance to them. The Anti-Social Behaviour Act 2003 relates to high hedges and allows councils to take action where “reasonable enjoyment of a property is being adversely affected by the height of a high hedge situated on land owned or occupied by another person”. See our advice on legislation for further details.