How to sharpen hedge trimmer blades

Signs your blade needs sharpening

A sharp trimmer cuts cleanly through stems within its tooth gap. Look for these signs that it is getting blunt.

• Stems are crushed or torn rather than cut
• The hedge face looks ragged and brown a few days later
• The trimmer stalls in growth it used to cut easily
• You can see rounded or nicked cutting edges on the teeth

Safety first

Remove the battery or unplug the trimmer before you touch the blade. Wear thick gloves, because the teeth are sharp even when blunt. Clamp the trimmer or the blade so it cannot move, and work in good light.

Note:Never sharpen a trimmer with the battery fitted or the plug in. Follow the maker's instructions; some blades should only be sharpened by a service agent.

Clean the blade

Sap and resin build up between the blades and make cutting harder even when the edge is sharp. Brush off leaves, then use a blade cleaner or warm soapy water on a cloth to remove sticky resin. Dry the blade thoroughly. Cleaning often solves a trimmer that seems blunt.

A combined cleaner and lubricant spray made for hedge trimmers does both jobs and leaves a light protective film.

File the cutting edges

Most hedge trimmer teeth have a bevelled cutting edge on each side. Match the existing angle with a flat file and stroke in one direction only, from the inside of the tooth towards the tip. A few even strokes are usually enough. Count your strokes so each tooth gets the same treatment.

1. 1

   Clamp the trimmer so the blade is steady

2. 2

   Find the existing bevel on one side of a tooth

3. 3

   File along the bevel in one direction, three to five strokes

4. 4

   Repeat on the same side of every tooth on the top blade

5. 5

   Turn the trimmer over and do the other side and the second blade if it is double sided

6. 6

   Remove burrs from the flat side with a light stroke or a fine stone

Lubricate and test

Wipe away filings and apply a light oil or hedge trimmer lubricant along the blade. Run the trimmer briefly so the oil spreads between the blades. Test it on a few stems: a clean cut means the job is done. Some trimmers also have a gearbox that needs grease at intervals; check the manual for the grease point and the right type.

When to replace the blade instead

Replace the blade if teeth are bent, cracked or missing, if the blades no longer sit flat against each other, or if heavy damage needs more than a light touch up. Replacement blades are model specific, so use the part number from your manual. For battery tools, a blade replacement is often good value if the motor and battery are fine.

Our hedge trimmer sizing guide explains blade lengths and tooth gaps if you are choosing a new trimmer instead. If you also need to sharpen your mower, see how to sharpen or replace mower blades.

Keeping blades sharp for longer

A few habits make a big difference. Clean and oil the blade after every session, before resin dries on. Avoid cutting near wire fences, stone walls and anything hard the teeth can catch. Do not force the trimmer into stems thicker than the tooth gap; cut those with loppers first. Store the trimmer dry with the blade cover on.

Over winter, give the blade a thorough clean, a light coat of oil and store it somewhere frost free. For battery tools, store the battery as the maker recommends; our guide to storing batteries over winter applies to hedge trimmer batteries on the same platform.

If your battery system is shared with a mower, the same brand's hedge trimmer is often sold as a bare tool. Our cordless mower and strimmer sets show which platforms cover several garden tools.

Frequently asked questions

Can you sharpen electric hedge trimmer blades? Yes, many can be touched up with a flat file. Check the manual, as some coated blades should go to a service agent.

How often should hedge trimmer blades be sharpened? When they start tearing rather than cutting. Cleaning and oiling after each use keeps them sharp for longer.

Do I need to take the blade off to sharpen it? Not usually. Clamp the trimmer securely and file the teeth in place.

What lubricant should I use on hedge trimmer blades? A hedge trimmer cleaner and lubricant spray, or a light machine oil, unless your manual says otherwise.