How to trim hedges: turn your privacy screen into a living feature wall

How to trim hedges

A beautiful and healthy hedge makes a perfect frame for any garden. Our guide gives you all the information and plenty of tips on how to trim hedges.

When to cut your hedge

It’s no surprise that hedges are so popular in our gardens: as a privacy screen that is also a beautiful green wall, a hedge serves as a great functional feature in any outdoor living space. But a hedge needs regular attention, trimming and maintenance to grow into a strong, dense form and to look its best for many years to come. It’s worth knowing exactly when and how to cut your own hedge for the most successful results.

The best time for a trim

Some plants benefit from a ruthless chop in February, and others don’t need cutting back until later in the year. For particularly fast-growing plants – or even if you just want a really neat hedge – you should actually trim twice a year.

Prune and rejuvenate overgrown hedging in February

From the middle to the end of February, before they set bud, hedging plants are not yet full of sap and so can take some generous trimming if needed to keep them in bounds. What’s more, there won’t yet be any breeding birds to disturb in the branches. Now is the time for trimming hedges such as box, thuja and coniferous cypress.

Cutting hedges back early in the year encourages strong new growth, particularly in hornbeam and field maple. This means it’s also a good time to tackle overgrown hedging that needs dramatic reshaping or rejuvenating. If you have a very overgrown hedge, it’s advisable to prune it back hard only on one side at first, so the plants recover a little, before trimming back the other side next February.

Close-up of a stem about to be cut by a long-reach hedge trimmer

Prune flowering hedges after they bloom

To prune flowering hedges such as forsythia, viburnum and jasmine, you’ll need to wait until later in spring, letting the plants flower before you get to trimming. Make sure you don’t disturb any nesting creatures when you do so.

Many hedges also get a second flush of flowers in summer, and these can be trimmed again after blooming at the end of June or start of July if it is not too hot. But remember, this second trimming should be light, and just for the purposes of keeping your hedging tidy.

Pruning at the end of summer

August is the right time to trim your beech, privet and evergreen hedging; beware with conifers though, as leaving trimming too late after this month can cause permanently bare patches.

Hedge trimming and the law

There are legal considerations that must be taken into account when trimming hedges: in the UK, the Wildlife and Countryside Act of 1981 states that you may not cut a hedge back if you know there is a nest present, and if cutting the hedge will damage or disturb the nest. These rules are very important for protecting wildlife, but they don’t prevent you from trimming your hedge: just be certain there are no nests in it first.

The right conditions for trimming hedges

Tip #1: Don’t trim your hedge if it is too hot or sunny. This is because if the leaves inside your hedging are suddenly exposed to bright sunlight, their sensitive dermal tissue could get burned.

Tip #2: An overcast, cloudy day is ideal for hedge trimming, particularly in summer.

Tip #3: While spring temperatures are still regularly dropping below -5°C, it’s too early for hedge trimming. Any cuts you make now will take a long time to heal, and the cold will affect thin branches in particular, making them brittle and weak.

A woman wearing safety glasses and gloves trims a hedge into shape using STIHL HSA 25 cordless shrub shears

When should I cut back young hedges?

Before a hedge is established, trimming and pruning is particularly important to ensure your plants are strong, dense and the right shape for your garden. For the first 2–3 years, hedging shrubs such field maple, hornbeam and beech need to be cut back by up to a third at the shoot tips early on in the gardening calendar, to encourage plenty more branches to grow.
Conifers and evergreen trees (such as thuja, cypress, bay and yew) need to be left untouched for a year to grow well. From the second year onwards, cut the side shoots back every year; once they reach the desired height, cut off the leading shoot.

When is hedge trimming legally permitted?

The law (Wildlife and Countryside Act of 1981) prohibits you from cutting back hedges if you know there are nests present, in order to protect animals and birds. With this in mind the RSPB recommends not cutting your hedge between March and August, though gentle trimming should not be a problem as long as you don’t interfere with the bulk of the hedge and cause damage there.

How often should I trim my hedge?

Lots of amateur gardeners get their annual trimming done towards the end of June, but in fact for most hedging plants, it’s worth cutting them to your preferred height and width in the middle to end of February. Then in summer they just need to be lightly pruned.

How often do particular hedge plants need to be trimmed?

  • Once a year: yew, barberry, cherry laurel, thuja and cypress.
  • Twice a year: privet, hornbeam, field maple and common beech.

Trimming your hedge stimulates growth each time you do it. Frequent but light trimming means it will grow more dense over time – provided that it gets enough water, warmth and light.

Tips and techniques for hedge maintenance

Keeping your hedge neatly trimmed encourages growth and keeps the hedge looking dense and healthy. These tips will help you to avoid bare areas and irregular hedges.

Close-up of the teeth of a STIHL HS 82 hedge trimmer and a cut stem

How to trim your hedge

On side shoots only, cut back new growth by two thirds. Leave main stems to grow until the hedge reaches the desired height. The only way to rejuvenate an irregular, patchy or misshapen hedge is with radical hard trimming and then reshaping. Take care with conifers here though, as they will not put out new growth if you cut them all the way back to the wood. The only exception to this rule is the yew, which can withstand even brutal pruning.

Do be aware that some plants, such as thuja and yew, can trigger allergic skin reactions, so you should always wear gloves when trimming these hedges.

The ideal weather for hedge trimming

Do not trim your hedge when it is too hot or sunny, as there is a danger that the freshly cut surfaces will dry out and die. The same applies if it is too cold, so if when spring comes you are still regularly experiencing sub-zero temperatures, do not trim your hedge: the cuts will take a long time to heal and the cold will weaken thinner branches.

How to trim your hedge straight

For a good straight cut, it’s helpful to have a guide edge to follow that runs parallel to the hedge. This could be the edge of the lawn or a kerbstone – or alternatively, you could put up a taut string between two stakes to keep you in line. Hold the hedge trimmer level as you work. You should step back every so often to check from a distance how the hedge is shaping up – this makes it easier to see if you are actually trimming straight or not.

A wedge for your hedge

For a lush look from top to bottom, go for a slightly wedged shape when trimming your hedge: wide at the bottom and narrow at the top. This is to ensure that light reaches the lower branches, otherwise they will lose their leaves for good. In any case, always ensure that the hedge is not wider at the top than the bottom, as if the bottom is too narrow it will suffer from being constantly in shade.

Trimming and pruning young hedging plants

When you plant a new hedge, it doesn’t need trimming initially. In its second year after planting, you can trim the hedge back to the shape you want. Leave the main stem alone until the hedge has reached its intended height, and cut all other stems back by up to half.

Filling gaps in your hedge

The solution for improving fullness in the appearance of a hedge is generally simple: plenty of light. Small gaps will quickly close up if they get enough light – so remove some surrounding branches or other growth that is shading the gap. For a larger space, fix a bamboo cane or other support across the gap and tie a nearby branch into it. The trained stem will follow the cane and grow in place.

Collect green waste

After hedge trimming, remember to dispose of the clippings. If leftovers remain on the lawn, they will obstruct its growth and may result in bald spots. It is best to sweep the green clippings together with a fan broom or remove them with a cordless blower, such as the STIHL BGA 56. Alternatively, before trimming the hedge you can spread out a textile underlay such as an old bed sheet to collect the green clippings. This saves a lot of work, especially in hedges with very small leaves such as boxwood, because the cuttings can be collected and disposed of so easily.

How tall can I grow my hedge?

The permitted height of a hedge depends on its location. In many places, two metres is the maximum. Contact your local council to avoid any problems.

Overhead view of a woman wearing safety glasses and gloves trimming a tall hedge with a STIHL HSA 56 cordless hedge trimmer

Hedge trimmers and long-reach hedge trimmers

When it comes to trimming hedges or freestanding topiary, you need the right tool – STIHL hedge trimmers and long-reach hedge trimmers will help you to whip any hedge or shrub into shape. Whether you’re a landscaping pro or a domestic gardener, you will find the right tool for every task in the extensive STIHL range.

Hedge trimmers

Our hedge trimmers were created with professionals in mind, so they have been effectively designed and built for long continuous use. The same advantages apply when trimming in your own garden too. Our tools really come into their own when working on hip- to chest-height hedges, as their ease of handling enables you to work very precisely and even to create intricate topiary shapes with your trimming.

Long-reach hedge trimmers

If you have a particularly wide or high hedge and need increased scope, we recommend a long-reach hedge trimmer. Available in short or long shaft versions, they are ideal for landscape maintenance professionals and ambitious private users alike.   

Cordless hedge trimmers

If you want to keep the peace when trimming your hedge but aren’t willing to sacrifice cutting performance, our 36 V cordless hedge trimmers are the best tools for you. Equipped with a powerful lithium-ion battery, these tools can achieve a high stroke rate.

See STIHL cordless hedge trimmers >>

Electric hedge trimmers

STIHL electric hedge trimmers cut precisely, boast ideal cutter geometry, and run quietly yet powerfully. The balanced weight distribution ensures excellent handling when trimming.

See STIHL electric hedge trimmers >>

Petrol hedge trimmers

Powerful STIHL petrol hedge trimmers are perfect for trimming work on large properties and for park and landscape maintenance. Working cable-free means unencumbered ease of movement.

See STIHL petrol hedge trimmers >>

Technique for cutting medium hedges with a hedge trimmer

For trimming the vertical sides of a hedge: Making circular movements, use both sides of the hedge trimmer to cut the flat faces of the hedge – remember to slightly taper towards the top, particularly on high hedges.

For trimming the top of a hedge: As you cut across the top, move the cutter bar horizontally at an angle of zero to ten degrees. Here’s a tip: if you use crescent-shaped movements, the clippings will fall away from the hedge.

A dark green hedge is trimmed using a STIHL HSA 56 cordless hedge trimmer
A woman wearing safety glasses trims the top of a low hedge in front of a large, bright house using a STIHL HSA 45 cordless hedge trimmer

Technique for using a long-reach hedge trimmer on a high hedge

For trimming the vertical sides of a hedge at a distance: When trimming vertically and working at a distance, set the cutter bar to the appropriate angle; if working at close range, use a straight cutter bar.

For trimming the top of a high hedge: With the cutter bar appropriately adjusted, even overhead trimming work on very high hedges is easy.

A man wearing protective clothing trims the vertical face of a tall hedge, using a STIHL HL 94 long-reach hedge trimmer.
A man wearing protective clothing trims the top of a tall hedge using a STIHL HL 94 long-reach hedge trimmer.

What is the difference between long-reach hedge trimmers and standard hedge trimmers?

STIHL hedge trimmers have been developed specifically for long rows of densely grown hedging. The double-sided cutter is ideal for pruning as well as horizontal and vertical trimming.

The extended shaft of a STIHL long-reach hedge trimmer means you can trim particularly tall, long or wide hedges. The cutter bar can be rotated by up to 145°, so you can set any angle with ease.

Tall, crisply trimmed square hedge next to trees in front of a blue sky
Close-up of a green leaf with edge cut by a hedge trimmer

From trimming to topiary

Some gardeners opt for annual trimming to keep things looking neat, while others release the artist within when it comes to their shrubs and bushes.

Cutting geometric shapes

Set up taut strings or a frame of wooden slats to help cut precise geometric shapes, even on plants with a tall trunk. Just rotate the frame around the plant, trimming off all protruding shoots as you go – it’s as simple as that, and a huge range of designs is possible with this method.

Interesting facts about shaping bushes

What is topiary?

The term topiary is derived indirectly from the Latin word topiarius, meaning ornamental garden, and is today used to refer to the shaping of plants. A topiary is simply a plant that has been intricately shaped, and the skill of doing it is widely considered to be an art form.

Which plants are best for topiary?

Dense shrubs such as box and yew are ideal for topiary.

How do you shape a hedge?

The main “bones” of the desired shape are created with strong branches, which become more and more fine as each stem progressively splits. Tie in flexible branches with wire to train them in the right direction for your preferred shape.

View over a formal topiary garden containing geometric hedging borders and topiary balls, with tall cypress trees in the background.

How to trim shrubs and bushes into creative shapes

For trimming bushes into animals and other creative shapes, it’s best to use a wire mesh structure. This should be installed around the entire shrub, then you can simply cut the shrub just outside the shape of the mesh.

  • You’ll need hand-held, sharp secateurs or another tool that you can cut precisely with.
  • Cut back all protruding stems several times a year to encourage the plant to fill out.
  • You’ll probably need to wait a couple of years, but eventually your project will make a striking garden sculpture.

Summary: trimming hedges

  • Trimming of overgrown hedges is ideally done in spring, shortly before new growth starts
  • For flowering hedges, trimming should only take place after they have finished blooming
  • If you’re planning a light trim in summer (March to September), make sure that there are no birds’ nests or other breeding creatures in the hedge
  • The best weather for hedge trimming is neither too hot nor frosty, and with no strong direct sunlight
  • Cut new stems back by two thirds
  • Use a hedge trimmer for chest-height hedges and a long-reach hedge trimmer for tall hedges
  • Create topiaries from shrubs and bushes using homemade frames

How do you trim hedges?

How you trim hedges depends on the effect you want – very formal hedges need more frequent attention. A hedge trimmer gives great results, and long-reach versions are available for very tall or wide hedges.

How do you trim hedges with an electric hedge trimmer?

An electric hedge trimmer makes easy work of hedge maintenance. Wear appropriate protective gear and tackle the sides of the hedge first: use circular movements to take off up to a third of the length. When cutting the top, using a crescent motion ensures the cuttings fall away from the hedge. A cordless hedge trimmer is particularly easy to handle and also quieter to use.

How do you trim hedges straight?

Trimming hedges straight requires a little preparation: set up a taut string between two stakes as a straight line to guide you. Alternatively, use a kerbstone or something else that runs parallel to the hedge. It’s not advisable to attempt doing this by eye!

When do you trim hedges?

You can trim hedges twice a year, generally in very early spring and then later in summer. The early pruning can be quite drastic if that’s needed, but go more lightly in summer – and don’t choose too sunny a day, as your plants may suffer. For flowering hedges, let them bloom before you trim them.