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How do I cut a hedge?

By Adele Dyer

Keep your hedges looking their best. Read our advice to make sure your hedges stay looking trim and smart year after year. 

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Watch our video to find out the best way to cut a hedge. 

How to cut a formal hedge

A formal hedge is one that is clipped regularly. Choose a dense, fine-leaved plant, such as privet or a conifer, and trim it regularly to a squared shape, or preferably to a wedge shape with the base wider than the top. This allows maximum light to reach the base and looks more solid. Try to keep the top no wider than about 60cm, so you can cut it easily from one side.

For longer hedges, erect a line using bamboo canes and string that does not stretch when it is pulled. Push bamboo canes well into the soil at either end of the hedge, and shorter canes at 45o to these, pointing away from the hedge. Tie a string line between the slanting and upright canes to stop the upright canes pulling inwards when you tighten the string along the hedge. Tie the string above the hedge to get a straight side and then about 1cm below the desired eventual height to cut the top. This stops you from cutting so close to the string that you nick it and have to retie it.  

When using a hedge trimmer, start at the bottom of each side and work upwards in smooth, continuous swathes. Cut the top of the hedge last.

Save time by spreading a plastic sheet beside the hedge to catch the clippings. Brush or rake the clippings from the top of the hedge, or they’ll look unsightly. If you leave them on the hedge, the damp, airless conditions they create could allow fungal diseases to get a hold. 

How to cut an informal hedge

Choose a large-leaved deciduous plant, such as forsythia, escallonia or berberis, which have bright flowers and berries, too. Native plants, such as hawthorn, blackthorn or field maple, are great for wildlife, while dog rose and sweet briar rose have attractive flowers and hips. 

For a regular shape you will need to cut back informal hedges after flowering. However, if you prefer a more relaxed-looking hedge with berries and hips, cut back hard every few years. 

You may prefer to cut these hedges with secateurs and loppers, selectively removing older branches for a more natural look.

How to cut the top of a hedge

Never lean a ladder against a hedge to cut the top. If you are using an ordinary step ladder, get someone to hold it steady for you. The best option is to work from a firm, level platform. There are plenty of options available, including raised platform systems that use side supports. Ideally, it should be high enough that you can cut the top of the hedge at waist height.

If you have a lot of tall hedges to cut, invest in a special hedge-cutting platform with a wide base suitable for non-level ground. These are available from suppliers such as Henchman and Hedgemaster.

Or you could look for a long-reach hedge trimmer with telescopic handles that extend by an additional 20-30cm or a long fixed shaft. You can angle the blade at right angles to cut the top of a hedge (up to about 3m high). 

Read more about long reach hedge trimmers. We've tested cordless, corded electric and petrol models.

How to renovate a hedge

Look at our guide on when to cut a hedge

All conifer hedges except yew should not be cut back beyond the green growth as they will not regenerate. If your conifer hedge has grown too large, it may be time to replace it. 

Decide on the height or width you want and use canes and string to mark this out before you start to cut. This will give you an idea of the size the hedge will be once it has been cut. 

Most hedge plants respond well to hard pruning provided you cut them at the right time of year.

You can cut back up to 30cm further than this, depending on the overall size of the hedge, to allow for new growth. To retain a physical barrier, and to avoid shocking the plant, cut back one side of the hedge one year and the other side the next, especially on large hedges. 

Use loppers or a pruning saw on older branches that are more than around 1cm in diameter. On older hedges you might have to cut most of the hedge this way, so leave yourself plenty of time to cut and dispose of the pruning. 

Once you've cut it back to the required size, trim regularly with a hedge trimmer. Go to our hedge trimmer reviews to find one to suit you and your garden.

How to use a hedge trimmer safely 

Hedge trimmers have some obvious dangers: they have sharp blades that are designed to snip through hard, woody stems and can easily cut other things, including you. 

Always work from the ground where possible, working on an even, dry surface. If you need to cut a tall hedge, use a long-reach hedge trimmer or a platform. 

If you opt for a mains hedge trimmer:

  • Always use a residual current device (RCD) plug or adaptor to protect you from an electric shock if you do accidentally cut the cable, unless your whole house is protected by an RCD.
  • It's all too easy to cut the cable, so keep it out the way by putting it over your shoulder so it hangs behind you, or attach it to your belt.
  • Make sure your extension cable is long enough to complete the job without stretching.

Any other safety advice?

  • Wear safety goggles or a visor to protect your eyes from flying debris.
  • If you have young children, unplug a mains hedge trimmer at the mains or remove the battery from a cordless trimmer if you leave it unattended for any time.
  • Strong gloves and work boots with good grips are advisable.

What about birds nesting in my hedge?

Many garden birds, including blackbirds, song thrushes, robins and hedge sparrows, regularly nest in hedges. It is illegal to knowingly damage an active bird's nest, and if disturbed birds may abandon their eggs.

If you have to trim hedges during the main nesting season - usually from March to the end of August - check for nesting birds first. Any nest site should be obvious from the frequent comings and goings, so keep an eye out for a few days before you plan to cut the hedge. Delay trimming until you are sure the nestlings have flown. If in doubt, wait until the autumn.

Alternatives to using a hedge trimmer

  • If you have lots of boundary hedges, a powered hedge trimmer is the best option.
  • If you only have a small hedge, the environmentally friendly, low-tech option is a decent pair of hedging shears.
  • For topiary, you can use ordinary garden shears, but topiary shears give a great finish. These can be used one-handed.
  • Large-leaved plants, such as laurel, can be difficult to trim cleanly with a hedge trimmer. Use a pair of secateurs to tidy up leaves left ragged by the trimmer.
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