Why sharp secateurs matter in the UK garden

If there is one tool that earns its keep in a British garden, it is a good pair of bypass secateurs. From cutting back the buddleja in March to tidying the roses in November, they are in your hand more than almost anything else. Yet many of us put them away dirty, blunt, or with a smear of sap welding the blades together.

Blunt secateurs do more than make hard work of a simple job. They crush and tear stems rather than slicing cleanly, leaving ragged wounds that are slow to heal and an open door for disease. A clean cut, made with a sharp blade, closes over far more readily. Keeping your pruners in good order is one of the kindest things you can do for your plants — and for your wrists.

The right cut, and the signs your blades need attention

Bypass secateurs cut like scissors, with a sharp curved blade passing a flat hook. That is the right tool for living wood; anvil secateurs, which chop against a flat block, are best kept for dead wood where crushing does not matter.

You will know it is time to sharpen when you notice any of the following:

• Stems are left with a bruised, white, frayed end rather than a clean slice.
• You find yourself squeezing with two hands, or pushing the branch against your leg for leverage.
• Thin stems slip sideways between the blades instead of being cut.
• The blades have a shiny, rounded edge when held up to the light.

Most gardeners should sharpen a pair that is in regular use two or three times a year, and give them a quick touch-up whenever a big pruning session is coming.

Cleaning sap, rust and grime

Before any sharpening, the tool must be clean. Sap is sticky, acidic and surprisingly corrosive, and it will clog a sharpening stone as surely as it clogs the blades.

Warm soapy water and an old toothbrush will shift most debris. For stubborn, dried sap, wipe the blades with a little methylated spirit or a dedicated resin remover on a cloth — work outdoors or in a well-ventilated spot, and keep it away from your skin where you can. A green scouring pad deals with light surface rust; for anything worse, a few minutes with fine wire wool and a drop of oil will bring the metal back.

Dry everything thoroughly with a rag. Rust begins within hours on a damp blade, so this step is not one to skip. Pay attention to the pivot, the spring and the little recesses where the blade meets the handle, as these are the spots where water lingers.

How to sharpen a blade properly

You need only a few simple things: a fine diamond file or a small sharpening stone, a cloth, and a little light oil. A file is ideal for a curved bypass blade because it follows the bevel easily.

Work through these steps:

• Disassemble if your model allows it — many secateurs have a single nut or screw at the pivot that lets you separate the blade from the hook. This makes the job far easier and safer.
• Identify the bevel. Only the angled side of the blade is sharpened. The flat back stays flat.
• Hold the file at the same angle as the existing bevel — usually around 20 to 25 degrees — and push it along the curve in one direction, away from the cutting edge. Do not saw backwards and forwards.
• Use light, even strokes, counting them so both sides of a pair get the same treatment. Five to ten passes is often plenty for maintenance.
• Turn the blade over and lay it flat on a fine stone to remove the tiny burr that forms on the back. Two or three gentle passes are enough.
• Wipe away metal filings and test the edge on a piece of soft paper or a green twig. It should slice, not chew.

Never use a power grinder on secateurs. It removes metal far too quickly, overheats the edge and takes the temper out of the steel, which means the blade will never hold an edge properly again.

Reassembling, oiling and adjusting

Once the blade is sharp, put the tool back together and check the tension. The pivot should be snug enough that the blades meet along their whole length, but loose enough that the handles open smoothly. A quarter turn on the pivot nut is often all that is needed.

Apply a few drops of light machine oil to the pivot, the spring and any moving parts, then open and close the secateurs a few times to work it in. A thin film of oil on the blades themselves will slow rust and help sap slide off next time. Some gardeners keep a lightly oiled rag in the toolbox for a quick wipe at the end of a session.

Finally, check the spring and the locking catch. Both are inexpensive to replace and are the usual reason an otherwise good pair of secateurs ends up in the back of a shed.

A year of good habits

Secateurs reward a little regular attention. In spring, as the sap rises and pruning gets busy, give them a clean and a sharpen before the season really starts. Through summer, wipe the blades after cutting anything sappy, such as conifers or fleshy shrubs, and re-oil the pivot. In autumn, when the big cut-back begins, a sharp edge saves real effort on thicker stems. And over winter, when the tool is quieter, take it apart properly, sharpen it, deal with any rust and store it somewhere dry — a hanging hook in a shed or a toolbox drawer is far kinder than a damp bucket on the floor.

Look after your secateurs and they will last for decades. More importantly, every cut you make will be a clean one, and your plants will thank you for it.