Secateurs and loppers
Secateurs become blunt with use and misuse, making them difficult to use and causing damage when pruning. It is a good idea to have a best pair for pruning and a cheap second pair for jobs like cutting back herbaceous plants.
Check to see if your pair of secateurs can be taken apart for maintenance. Not all can be dismantled. Secateurs can be sharpened with a whetstone, diamond tool or sharpening steel. Here we look at some step-by-steps using a diamond tool. This technique is also suitable for loppers that can be taken apart.
How to sharpen secateurs with a diamond tool
- Loosen and remove the central nut. Carefully disassemble the parts on a piece of kitchen towel or cloth. Spray with WD-40 to soak and loosen dirt.
- Clean your blade before sharpening, to reveal its condition.
- Handheld blade sharpeners generally don’t require oil but could have a coarse and fine side, so start with the coarse side.
- Sharpen the angled side of the blade only. Hold the blade steady and run the diamond tool away from you. Apply even pressure along the blade to expose some new shiny metal, not forgetting the tip. To help with sharpening the blade evenly, mark it with a marker pen, this will be removed as you sharpen and highlight missed sections of blade.
- You can buff along the blade in a circular motion, but do finish with a couple of sweeps to smooth the metal in one direction.
- Check the blade with every sweep. Blunt and damaged blades take longer.
- Use the fine side of the diamond sharpener to give a smooth finish to the blade; 2-3 sweeps should do it.
- Check for a burr on the flat side of the blade. Remove by running the diamond sharpener flat across until it’s removed and smooth to touch. Do not sharpen the flat side of the blade, as this will affect the cutting bite.
- Once clean, reassemble. Put a few drops of general purpose oil or a smear of Vaseline onto the central pivot and spring, to improve movement and reduce stiffness.
- Test sharpness by cutting into a sheet of paper. It should cut cleanly with minimal effort. A blunt pair or secateurs would fold and crush the paper rather than cut.
For loppers and secateurs you can’t take apart, clean the blade as best you can and use the same sharpening motions as above on the open blade. Angle the blade away from you, firmly pushing the sharpening tool. A pocket sized diamond sharpener or sharpening steel is ideal for this and for sharpening on the go, during a large pruning job.
Garden shears
Some garden shears (hedging shears, 'sheep' shears and lawn edging shears) come with a specially-designed sharpener, specific to that brand of shears. Others could be sharpened with general sharpening tools but this is a tricky job if the blades do not come apart or the shears are very blunt. Where this is the case it is usually best to have them professionally sharpened.
Garden knives
There are several types of garden knives, each with their own purpose and differently shaped blade: a general garden knife is a traditional pocket knife; a pruning knife has a curved blade; a This involves joining the roots of one plant to the stem of another related plant, so they fuse together to form one plant. There are various methods, all requiring great skill. Grafting is mainly carried out by commercial growers to combine one plant’s qualities of flowering or fruiting (the upper section or scion) with the vigour or resilience of the other (the roots or rootstock). Fruit trees are often grafted, along with a few ornamental shrubs and trees, and in recent years grafted vegetable plants (mainly tomatoes, but also chillies, cucumbers, aubergines, etc) have become available.
grafting knife has a rectangular blade. A general purpose knife will only need sharpening as required. Grafting and propagation knives need to be razor sharp for best results. As with secateurs, garden knives can be sharpened with a whetstone, diamond tool or sharpening steel. Here we look at some step-by-steps using a whetstone.
How to sharpening a garden knife with a whetstone
- Clean the blade with WD-40 before starting.
- Prepare your stone before use. Apply a couple of drops of general purpose oil to the abrasive side of the stone or soak in water for 5-10 minutes, depending on the type of stone. Spread the oil to create a thin film across the stone. Water should sit as a fine film across the stone after soaking.
- Knife blades can have one or two sides to sharpen. Pocket knives usually have one bladed side and one flat, like secateur blades. Pruning knives have two sharpened sides, like a kitchen knife. Check before starting.
- Push the blade up the stone away from you with firm controlled pressure, in one motion keep the blade running along the stone, at the acute angle of the blade.
- Check with every sweep of the stone, looking for newly shiny metal that is smooth, sharp and evenly exposed. Blunt and damaged blades will take longer.
- Prepare the fine side of the stone with oil or water, before finishing the sharp side of the blade with 2-3 sweeps.
- With a double sided blade sharpen both side evenly, to keep the blade balanced.
- On a single sided blade check the flat side for a sharp burr. Remove this by running the flat side of the blade, flat across the stone a couple of times. Do not sharpen this side of the blade as this will affect the cutting impact.
- Test sharpness by holding up a sheet of paper and gently resting the blade on the top edge. The knife should cut through with minimal effort.
- Wipe the blade clean and store somewhere clean and dry.