Hedge Trimming: How Often and When

A good hedge is one of the most useful things in a garden. It gives privacy, filters the wind rather than blocking it like a solid wall, softens a boundary and gives birds somewhere to live. It also keeps growing, and a hedge that has been left for a couple of seasons can take over a surprising amount of a small garden.

How often you cut depends on what the hedge is made of and how neat you want it. This guide covers the common garden hedges we see across South Wales, the usual timing for each and the care needed around nesting birds. Hedge work is part of our tree surgery and hedge care service.

A rough guide by hedge type

These are general patterns rather than fixed rules. Growth varies with the weather, the soil and how sheltered the garden is, and a mild, wet year in the valleys can mean more cutting than usual.

• Privet and Lonicera nitida: fast and dense, usually two or three light trims between late spring and late summer to stay crisp.
• Leylandii and other fast conifers: often two or three trims a year in the growing season. Leylandii will not regrow from old brown wood, so it must never be cut back past the green growth.
• Beech and hornbeam: usually once a year in late summer. Cut then, beech tends to hold its dry brown leaves through winter, which keeps some privacy.
• Yew: slow growing, usually once or twice a year in summer. Unlike most conifers, yew will regrow from old wood, so it can be cut back hard if needed.
• Laurel: usually once a year from late spring into summer. The big leaves look ragged when sliced by a trimmer, so for a neat finish on a small hedge, some people use secateurs.
• Hawthorn, blackthorn and mixed native hedges: often once a year, or every other year, in late winter, which leaves flowers and berries for wildlife.

Nesting birds: the most important timing rule

Hedges are one of the favourite places for garden birds to nest. By law, wild birds, their eggs and their nests while in use or being built are protected, and that covers every garden hedge. The main breeding season is often given as roughly March to August, but some birds start earlier or carry on later, depending on the species and the year.

That does not mean hedges cannot be touched all summer, which would not work for fast growers such as privet and Leylandii. It means each hedge should be checked carefully before cutting, by watching for birds flying in and out and looking into the dense parts. If there is an active nest, that stretch is left alone until the young have gone. We will work around a nest and come back later rather than cut through it.

Heavier cutting, reshaping and hard renovation are best kept for autumn and winter, outside the busiest part of the season. This is general guidance, not legal advice. For more on wildlife and permissions, see our article on tree and hedge permission in Wales.

Getting the shape right

The shape of a hedge matters as much as how often it is cut. A hedge that is wider at the bottom than the top, with gently sloping sides, lets light reach the lower branches and stays thick right down to the ground. One that is cut wider at the top shades its own base, which thins out and goes bare.

• Keep the top slightly narrower than the base.
• Use a line or a guide for long, straight runs so the top stays level.
• Take a little off often rather than a lot rarely, as dense hedges respond best to regular light trims.
• On exposed sites, a rounded top sheds wind and snow better than a sharp flat one.

Overgrown hedges and hard cutting back

Many hedges we see have been left to grow too tall and too wide. Most broadleaved hedges, including privet, beech, hornbeam, hawthorn and laurel, can be renovated by cutting them back hard, but it is kinder to the hedge to do it over two or three years: one side and the top one winter, the other side the next.

Renovation is usually done in the dormant season, from late autumn to late winter, for deciduous hedges, while evergreens are often done in mid-spring, which means a very careful nest check first and waiting if birds have moved in.Leylandii is the big exception: it cannot be cut back into bare brown wood and recover. If a Leylandii hedge has grown far too big, the realistic options are often to keep it at its current size, reduce it only as far as the green allows, or take it out and start again.

For a hedge that has become a jungle, with brambles, ivy and self-seeded trees growing through it, a garden clearance first may be the sensible start, followed by proper trimming.

Tall hedges and neighbours

In Wales, as in England, councils have powers to deal with complaints about high hedges that are mainly evergreen and over about two metres tall, where they affect a neighbour’s reasonable enjoyment of their home. The council would normally expect neighbours to have tried to settle it between themselves first. The details are set by the council and the Welsh Government, so check with your local council if a hedge is causing a dispute.

In general you can trim the side of a neighbour’s hedge that overhangs your garden, up to the boundary, as long as you do not harm the health of the hedge. A friendly word first avoids most arguments. If the hedge is to be replaced, a new fence is sometimes the simpler boundary, though it gives less shelter and wildlife value.

Hedge laying and new hedges

For older native hedges that have gone thin and gappy at the bottom, hedge laying is a traditional alternative to trimming. The stems are partly cut near the base and bent over to make a thick, living barrier that regrows from the bottom. It is winter work and suits country gardens and field boundaries, like those around the Black Mountains near Talgarth.

If you are starting from scratch, choose a hedge that fits the space and the time you have for trimming. A slower plant such as yew or beech needs less cutting than a fast conifer. Tony and the team can talk through the options, and trim, renovate or plant a hedge for you. Ask for a free quote any time of year.

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