A sharp tree trimmer is essential to easy and accurate pruning. Dull trimmers can cause damage to the tree's wood and make extra work for you. While many garden stores offer the service of sharpening tree trimmer blades for a fee, this is one task that can easily be done at home.
Clean the blades with a steel wool pad and some water. Rub all of the blade surfaces until all built-up dirt and plant matter is removed. The blades must be cleaned prior to sharpening or rocks and soil can be ground into the blade and ruin them completely.
Wipe the blades clean with a wet paper towel to remove any remaining soap.
Dry the blades and their joint completely with paper towels.
Moisten the sharpening stone in some water.
Follow the blade's bevel from the joint end to the tip, rubbing in a light circular motion. Repeat this motion five to six times, always going in the same direction.
Take a piece of hair from your head and touch it to the trimmer blade. If the hair cuts without much pressure, then the blade is sharp.
Dry off the blade again and use the trimmers.