1) Every winter, the advice comes to sharpen and clean tools, but it rarely includes instructions on how sharpening should be done. There is no doubt that good tools with sharp cutting edges make gardening much easier. If you try it, you will believe it. Better quality tools hold a sharp edge longer.
2) It helps to be able to hold larger tools firmly while sharpening and we prefer to do this in a simple workbench vice.
3) Only ever sharpen one side of a spade or push hoe – the side that faces upwards. With a push hoe, this keeps the blade flat to the ground with the cutting angle on the upper side. Spades cut better with one flat side and the upward or outward side bevelled and sharpened. We use a file to sharpen the blade. Home handypeople may go so far as to use an angle grinder but be careful not to overheat the garden tool or you will lose the temper (hardness) of the blade.
4) An oil stone is the best implement we know for sharpening secateurs and can be bought from a hardware store. Most secateurs are held together with a central bolt and nut. You have to unscrew this to take the blades completely apart. Some CRC or oil may help to loosen it. Do not lose the spring in the process.
5) Wetting the stone with oil, use a gentle circular motion to sharpen one side of the blade. Never sharpen both sides of the blade or you will find it no longer cuts (it is the same with scissors). Cutting relies on a sharp bevelled edge meeting a completely flat surface so always sharpen the side of the blade that is already bevelled. Where you have secateurs like these with one blade incurved, this second blade shown on the table will need to sharpened on a round stone or with a round file because it will not sit flat to this type of stone.
6) A quick-fix sharpen for secateurs and scissors can be achieved with this handy little tool from garden retail outlets. It is also the only way we know of sharpening cheap secateurs held together by rivet, or the grape snips with upward curving blades. Run it along the angled edge of the cutting blade about six times. Remember to sharpen only the bevelled side of each blade. This tool is made by Bahco though there are other brands on the market.