Dull pruners leave jagged edges, and these rough cuts leave the plant more susceptible to weather damage, disease and insect infestation. Keep your pruners sharp by sharpening them at least once annually. The best time to do this is in winter when you are not using them. Your first time sharpening the pruners will take the longest, and you don't want to be rushed by an impending project.
Clean the blades. Scrub dirt and rust off your pruners blades with soap, water and a brush. Dip the blades in kerosene to remove any sap.
Dry the blades off with a towel.
Use a permanent marker to color on the bevel on the cutting edge of the blades on your pruner.
Apply a thin coat of vegetable oil to the pruner's blades for lubrication.
Sharpen the blade using a medium-grain file. Start with the narrowest edge of the file near the joint, positioned at the same angle as the beveled edge of the blade. Move the file across the blade and down the file in one smooth stroke, continuing to follow the angle of the blade. If you are filing correctly, the marker will grind away evenly. If certain areas wear away quicker than others, adjust your filing angle until it is in line with the angle of the blade. Continue to file until all the magic marker is gone and the blade is shiny and sharp.
Test the blade for sharpness by pruning a twig. Sharp pruners cut easily and leave smooth pruning wounds behind.
Apply a thin coat of vegetable oil to your pruner's sharpened blades.