The cutting blade of anvil-style pruners comes down onto the center of a soft metal or hard plastic lower surface, called the anvil or table. Anvil pruners tend to crush the soft tissue of the stem, stopping the flow of nutrients, prolonging the healing time for the cut surface.
Despite the bypass pruner's benefits, garden centers still offer a nearly equal number of anvil-style pruners and loppers, a never-ending source of confusion for the gardener hunting for cutting tools.
So, we asked area garden experts their pruning preference: bypass or anvil?
The late Sacramento County Farm Advisor, Chuck Ingels, preferred bypass pruners. "I never use anvil pruners because you often can't cut close enough to the branch collar without leaving somewhat of a stub," said Ingels. "When they begin to wear, they often don't cut all the way through. Also, they crush the bark, which bypass pruners can do also, but you can turn the shears so the blade is closer to the collar and make a clean cut."
"I don't use and usually do not recommend anvil pruners," says Luanne Leineke, formerly the Community Shade Coordinator for the Sacramento Tree Foundation. "I tend to see too many wounded branches, particularly when the bark is soft. I suggest using bypass pruners for up to three quarters of an inch-thick branches, loppers for up to one inch thickness and a hand saw for anything larger."
Bottom line: Bypass pruners are much more versatile than anvil pruners. Every gardener should own a pair of bypass pruners.
But a word of warning: don't force cut a branch with bypass pruners that were not meant to cut a larger branch. Using too much force to work the blade through the wood could damage the entire unit. If those bypass pruners are advertised as cutting through one-inch branches, don't exceed that limit.
Move up to a larger cutting tool for those bigger branches, such as bypass loppers, a small branch saw (my favorite), a bow saw, or when you finally realize that "Life is too short to put up with a problem plant", a good quality chain saw.
Perhaps have a pair of small anvil pruners for the cut flower garden. And larger anvil ratchet loppers for removing dead wood.
Finally, whatever you purchase, buy quality. Look for pruning tools that have replaceable parts (blades, springs,etc) that can easily be disassembled for cleaning, sharpening, oiling, and maintenance.