Keep Your Pruning Tools Sharp! by Kristina Hughes, Clear Creek County Master Gardener

August 29, 2019

It's pruning season again! And while it can feel intimidating with complicated rules for when to prune each plant and how to make various kinds of cuts, one of the easiest ways you can be successful with pruning is to make sure your tools are sharp.

Why are sharp pruners so important?
Whenever you cut your plant, you are making a wound which is an opening in the plant's natural defenses. The wound creates an opportunity for diseases, fungi, bacteria and other pests to enter the plant and cause problems. The good news is you can minimize the damage from these pruning wounds.

Make clean cuts
Jagged, ragged wounds create more surface area in the nooks and crannies for pathogens to to enter the juicy, live plant tissue just under the bark. In contrast, a nice clean cut is easily compartmentalized by the plant's defense systems. When the cut surface is smooth, the plant can form a protective barrier around the wound and heal much more quickly.

Use sharp tools

Sharp tool blades are the best way to ensure your cuts are smooth. Sharp blades slice easily through the wood, rather than tearing or smashing the tissue. Your plant will thank you!

You'll notice another benefit: less strain on your body. When using a sharp blade, you won't have to work as hard squeezing the tool closed. So your wrists will thank you too!

Bypass pruners make clean cuts
Bypass pruners are generally recommended for most pruning tasks because they slice, rather than crush, the plant tissue, reducing the amount of damage the plant has to seal off. Bypass pruners act like a scissor, with the two blades sliding past each other.

How to sharpen your bypass pruning tools
You can clean the blades before sharpening, if you like. Alcohol is good for removing sap and steel wool can remove rust.

I find a picture is worth a thousand words, so I will refer you to the short video below which shows a simple method for sharpening a hand pruner. If the link doesn't work, google 'corona sharpening tool ac 8300' and look for a YouTube video that is 1:09 minutes long.

(Link to video: https://Youtube.be/glBHtVnbj7Q)

You don't have to use that specific sharpening tool. There are a variety of sharpening tools, some of which are pictured below. On the left is a diamond file with both a round side and a flat side. In the center is a simple mill file, available at any hardware store. If your pruner is very dull you may want to use a coarse file to remove a lot of material before switching to a finer file for finishing the blade.

So you really enjoy sharpening your tools?
If you want to get more detailed information on sharpening, Oregon State Extension has an easy to follow but quite thorough guide at (insert link: http://extension.oregonstate.edu/benton/sites/default/files/sharpgdn_insights2012.pdf). It explains how to sharpen loppers, hedge trimmers, saw teeth and also how to adjust the bolts on your pruners.

I think you will find it much more pleasant to work with sharp tools. It's simple to sharpen them and really quite satisfying to see the shine of a sharp edge. You'll be one step closer to mastering pruning. And your plants will be happier!