How to sharpen pruners safely and properly

Sharp pruners can help keep your plants free of disease and boost their resistance. Use this guide to know all that’s needed, like how to sharpen garden pruners, what’s needed for sharpening pruners, how to clean garden pruners, how to sharpen pruners the right way, which includes how to sharpen pruners with a whetstone. 

So read on to know how to sharpen this essential gardening tool and help keep your garden healthy!

What you’ll need

Here are the tools you’ll need for sharpening pruners and the necessary cleaning and rust removal before blade sharpening.

Safety equipment:

• Safety glasses or goggles

• Safety gloves

Disassembly tools:

• Spanner, hex wrench, or screwdriver

For cleaning/rust removal: 

• Rust and sap eraser or wire wool

• Coarse and fine-grit sandpaper

• Bucket or basin

• Clean water

• Dish soap

• Wire brush

• Tap or garden hose

• White vinegar

• Old rag or towel

For sharpening:

• Worktable

• Old rag or towel

• Pruner sharpener or sharpening stone for pruners/whetstone

• Diamond or steel file

• Machine oil

• Twigs of varying thicknesses

Time of completion

It can take about 20 minutes to sharpen your pruners. If your pruners were heavily used and not maintained, this can take more time.

If rusty, you may need another 12 to 24 hours of soaking them in a water-vinegar solution to get rid of a heavy layer of rust. 

How to sharpen pruners

Step 1: Clean the pruners

Remove any thick or stubborn dirt and debris. These coat the blades and prevent sharpening. Place the pruners under the tap to loosen or remove any dirt; you can also use a sharp blast from your garden hose if the dirt is difficult to remove. 

Use a rust and sap eraser for highly stubborn dirt and grime (you can buy this at a DIY center or gardening supply shop) or wire wool to rub them off. You can also clean the blades with dish soap, then give the pruners one final rinse. Wipe the tool dry with an old rag or towel after rinsing. 

Step 2: Remove rust

Equally important is removing any rust on the blades. If the rust is only a thin layer, you can use coarse or fine-grit sandpaper to scrape it off.

Use a water-vinegar solution for a thicker layer of more stubborn, set-in rust. Mix white vinegar with water in a 1:1 ratio in a bucket or basin. Immerse the tool in this solution for at least 12 hours or overnight to remove thick, encrusted rust.

Use a wire brush to scrape off the rust. Use soapy water to ensure complete rust removal, then rinse it with clean water. Dry the tool with an old towel or rag afterward. 

Step 3: Grind a new edge

If any parts of the blades have nicks or dull sections, you’ll have to grind a new edge. With a spanner, hex tool, or screwdriver, loosen and remove the retaining nuts and bolts that keep the tool together. Store the metal spring or coil for re-assembly later. 

Lay the handle of the upper blade on the edge of your workbench or work table. Make sure that the blade protrudes and faces away from you. Use a diamond or metal file to create a new cutting edge on the blade, applying long, slow strokes at the same angle as the blade’s bevel. 

Note that the bevel angle is usually between 20 to 30 degrees. Do as many strokes as needed until you see a new edge—a brightly-coloured line indicates this on the blade. Stop once you see that a new edge is consistent and visible on the blade.

For the lower “jaw” of the pruners, lay the handle on your work table with the jaw protruding from the table's edge and facing up. Use your diamond or steel file to flatten any nicks on the jaw. Aim to create a flat and even surface.

Retrieve the spring or coil, nut, and bolt, then reassemble the tool. Apply a spot of machine oil on the moving parts and open and close the pruners a few times to spread the oil evenly. 

Step 4: Sharpen the pruners

It’s common to use a whetstone to sharpen pruners. You can even sharpen pruners with a metal file if you have one and know how to sharpen pruner blades this way. You don’t necessarily have to disassemble the pruners when sharpening; just make sure that the sharpener consistently makes contact with the blade and no other part of the pruners.

Wear your safety glasses and gloves, and on with the sharpening!

Using a whetstone

First, submerge the whetstone in water until all the air is gone. You’ll know it’s ready when no more bubbles come out.

• Large whetstone - lay the blade on the whetstone at the same angle as the bevel

• Small whetstone - lay the whetstone on the blade at the same angle as the bevel

Make long, slow strokes a few times without lifting the tool or the whetstone. Don’t rush, and make sure every stroke is at the correct angle. After a few strokes, you should see a long, sharp edge on the blade. 

Using a metal or diamond file

Lay the pruners flat on your workbench. Hold it down so that the blade protrudes from the edge of the bench and faces away from you. 

With the file in your other hand, make long, slow strokes at the same angle of the bevel. Do this a few times until you see that the blade has a consistently sharp edge. Never lift the file to ensure consistent sharpening. 

Step 5: Test the blade’s sharpness

To make sure that the blade is sharp along its entire edge, test the pruners by cutting a few twigs of different thicknesses. Never run your bare fingers on the blade! Make a few cuts and inspect the twigs.

If the cuts on them are perfectly straight and have no frayed or rough edges, you’re done sharpening. If you still see rough edges on the twigs after cutting, repeat the process until the cuts are perfect.

Step 6: Store the pruners properly

After sharpening the pruners, don’t just toss them into a storage container willy-nilly. 

Apply a spot of machine oil on the blade and spring, then open and close the pruners to distribute the oil evenly. Hang the tool up on a hook in your garden shed. You can also fill a bucket with coarse sand dampened with machine oil, then store the pruners with the blades embedded in the sand.

What are the types of pruners, and which should I use?

There are many types of pruners. Here’s a quick rundown: 

1. Bypass

These pruners have two blades that pass each other (hence the “bypass” name). The purpose of its design is to provide clean cuts. Use these pruners to cleanly cut stems or branches 2.5 cm in thickness / an inch thick or less of living plants. 

2. Anvil 

This type of pruner is ideal for cutting dead, woody branches that are usually tougher for other pruners to cut or may cause their blades to become blunt. Anvil pruners do more of a crushing-and-cutting action on woody branches, thanks to their robust top blade that stops at an anvil-like blunt base. 

3. Double-cut

Consisting of two straight blades that converge at the center, double-cut pruners look like crab claws and are ideal for pruning fruit-bearing trees. Their heavy blades make it easier to cut clean through woody branches without damaging them, allowing the plant or tree to heal faster. 

4. Ratchet

Much like anvil pruners, ratchet pruners have a straight blade and a blunt base for bearing down on and cutting off dead stems or branches. Their ratcheting feature allows them to cut thicker, woody branches with repeated squeezes on the handles. 

So which type of pruners should you get? Most gardening experts recommend starting with a good pair of bypass pruners. As you make your first foray into gardening, bypass pruners are an appropriate and versatile tool for trimming and caring for many plants. Remember, you can always consult and hire an expert if you’re unsure how to cut and care for your plants.   

Maintain your gardening pruners

Getting into gardening may appear intimidating, but you can use this guide for all the essential knowledge about this worthwhile activity. Don’t forget that you can also post a task to get help with any of your gardening needs!