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How to trim a hedge properly: sides before the top

Updated: October 2026

You have a cordless trimmer and a hedge you can reach, and the usual failures are a wavy top, a flat battery, or a nest you did not look for. How to trim a hedge is the order of the work, not a shopping list. The [cordless hedge trimmer comparison](/hub/lawn-and-garden-equipment/cordless-hedge-trimmer) is where the model lives. This page assumes the tool is already chosen. We did not lab-test these machines. A qualifying purchase through our links can earn a commission at no extra cost to you. Nesting law is on [when you can cut a hedge](/hub/lawn-and-garden-equipment/cordless-hedge-trimmer/sub/cordless-hedge-trimmer-when-to-cut). Blade length is in the [cordless hedge trimmer buying guide](/hub/lawn-and-garden-equipment/cordless-hedge-trimmer/sub/cordless-hedge-trimmer-buying-guide).

You have a cordless trimmer and a hedge you can reach, and the usual failures are a wavy top, a flat battery, or a nest you did not look for. How to trim a hedge is the order of the work, not a shopping list.

Our top picks

VOERJIA VOERJIA 21V 50 cm

Best overall

VOERJIA VOERJIA 21V 50 cm
8.2/10about £64.99
View offer
Bosch Bosch EasyHedgeCut 18-45

Rank 2

Bosch Bosch EasyHedgeCut 18-45
9.0/10about £57.00
View offer
Yard Force Yard Force LH C41A

Alternative

Yard Force Yard Force LH C41A
7.8/10about £100.00
View offer
On this page
  1. 1.Before the blades move
  2. 2.Sides, then the top
  3. 3.Plants and packs that change the method
  4. 4.When you stop

Before the blades move

Look into the hedge before you start the motor. The Wildlife and Countryside Act 1981 makes it an offence to damage a wild bird's nest that is in use or being built. If you see a nest in use, or one being built, stop that section and leave it. A glance from the path is not the same as parting the growth you are about to cut. The Royal Horticultural Society advises goggles, thick gloves and sharp blades. A blunt bar tears rather than cuts. Cordless tools in this set are not a mains lead, so do not treat an RCD as if the pack were a cable. Where a listing describes a two-hand start, use it. You follow the control that is actually on the handle.

Sides, then the top

Cut the sides before the top. The RHS sequence works upward from the bottom so clippings fall clear of the teeth you have passed. Keep the cutter moving. On a formal hedge, set a string about 1 cm below the height you want. Cut to the string. Do not cut the string. A hedge that is wider at the top shades the base, and the bottom thins. Taller formal hedges are kept to a batter, a little wider at the base than at the top. Thrive uses the same order, sides then top, and suggests breaks before your arms tire. If you use a ladder, the RHS wants a stable platform and someone footing it. If the top is only reachable by climbing, that choice is on the pole hedge trimmer or handheld page.
VOERJIA VOERJIA 21V 50 cm

Testsieger

VOERJIA VOERJIA 21V 50 cm
8.2/10about £64.99
View offer

Plants and packs that change the method

Laurel looks shredded when a toothed bar tears the leaves. If the look matters, the RHS points you to secateurs for those shoots. Most conifers will not reshoot from old brown wood. Yew is the exception the RHS names. Cutting Leyland cypress back into bare wood leaves a brown face that does not green up. Which? points stems thicker than about 1 cm toward loppers. Forcing a 15 mm bar into wood that will not enter the teeth stalls the tool. Use loppers for that stem, then the trimmer for soft growth. The VOERJIA listing states about 30 minutes on each of two packs. That is a claim, and your hedge may be denser. If you have only one pack, charge it and finish later. Do not keep nudging a slowing bar through the last third, because the face tears. These listings do not print a noise figure.

When you stop

Stop when both feet cannot stay on firm ground, when the job is old wood rather than a trim, or when you are employed and the site needs a proper assessment of noise and vibration. None of these listings prints a decibel figure. Stop beside an overhead line. Extended-reach manuals for this class of machine say keep away from power lines, and that still applies to any bar you lift toward a cable. A longer session does not fix a hedge at the wrong height. Thrive notes that some seated gardeners are better with shears, because a long-reach tool is heavy. If the ladder, the wood or the line is the problem, put the trimmer down. The string only helps a hedge you can already maintain.

Common questions

Do I cut the top or the sides first?
The sides come first, working upward from the bottom so clippings fall clear. The top is last, to a string set about 1 cm under the height you want. Doing the top first drops debris onto the side you still have to see.
How do I get a straight top?
Run a string between two canes, about 1 cm below the finished height, and cut to the string without cutting it. Sighting along the bar with no line is how a top ends up higher at the gate than at the far end. On a long run, check the line from the path before you start the second half.
Should the hedge be wider at the top?
No. A formal hedge should be a little wider at the base than at the top, so the lower leaves still get light. A top-heavy shape shades the skirt, and the base thins. The RHS keeps taller hedges to that batter.
What do I wear?
Goggles and thick gloves, as the RHS advises, plus whatever keeps your forearms covered. The bar throws twigs back at your face, and a blunt blade makes that worse. Gloves do not make it safe to clear a jam with the pack still fitted. Take the battery off before you pick debris out of the teeth.
What if I find a nest?
Stop cutting that part of the hedge. Damaging a wild bird's nest that is in use or being built is the offence under the Wildlife and Countryside Act 1981. Leave the section until the nest is finished with. The dates, the farm-hedgerow ban and Northern Ireland are on the when-to-cut page.
What do I do when the battery runs out halfway?
Fit the second pack if the kit included one, and carry on with the same line. If you have a single pack, stop and charge it. Do not invent a runtime the listing did not print, and do not keep pushing a slowing bar, because the face tears. A stated 30 minutes is a claim about that pack, not a measurement of your hedge.

Related pages

Best cordless hedge trimmer

Cordless hedge trimmer

Cordless hedge trimmer buying guide: blade and gap

Pole hedge trimmer vs handheld for reach and weight

When can I cut my hedge UK: a nest, farm, or garden

Sources

Public UK sources and amazon.co.uk listings from the research digest, captured on 19 October 2026.

  1. Which? — How to buy the best hedge trimmer (retrieved 19.10.2026)
  2. RHS — How to trim a hedge (retrieved 19.10.2026)
  3. RSPB — Birds' nests and nestboxes (retrieved 19.10.2026)
  4. The Management of Hedgerows (England) Regulations 2024, regulation 3 (retrieved 19.10.2026)
  5. Anti-social Behaviour Act 2003, Part 8 (retrieved 19.10.2026)
  6. HSE INDG480 — Hand-arm vibration (retrieved 19.10.2026)
  7. Control of Noise at Work Regulations 2005, regulation 4 (retrieved 19.10.2026)
  8. BS EN 62841-4-2:2019+A1:2022 — Particular requirements for hedge trimmers (retrieved 19.10.2026)