When pruning your trees, avoid these common practices

by Stephanie Robinson

January 7, 2020

When we see something often enough, sometimes we assume that must be the best way to get the job done. Unfortunately, these pruning practices are common throughout the Sacramento area, and many people continue using them simply because that’s how they’ve always seen others do it.

When pruning your trees or hiring an arborist, make sure to stay away from these harmful practices:

Two large trees in a front yard have been topped, leaving only ugly stubs and unsafe, unhealthy trees.
Topping (heading)

Topping is cutting branches back to points without any lateral branches where they will become stubs. Most people who want to top their trees are looking to reduce risk by reducing the size of those trees. However, topping increases risk, severely weakening the tree and opening it up to decay. Once it’s done, it requires annual maintenance and ruins the natural beauty of the tree. Reduction cuts should be used instead. Learn more from the International Society of Arboriculture about why topping is harmful.

Ash trees in a commercial parking lot that have been lion-tailed - all foliage was removed from the lower 2/3 of branches, leaving all foliage and weight precariously hanging on branch tips.
Lion-tailing (stripping)

Topping is cutting branches back to points without any lateral branches where they will become Lion-tailing is a dangerous practice that leaves the branches mostly bare with foliage only at the ends (resembling a lion’s tail). Trees need foliage spaced evenly along branches to buffer impacts from wind, protect bark from sunburn, and produce food in their leaves through photosynthesis. Stripping away all of the foliage from the inner canopy will weaken the tree and potentially cause branches to crack and fall. 

A wound from a flush cut on a tree trunk, where a limb was removed inside the branch collar flush against the trunk.
Flush cuts

Flush cuts occur when a limb is pruned all the way back to the main branch or trunk. Pruning cuts should be made just outside the branch collar, which is the ridge where a branch meets the trunk and where trees have protective mechanisms that prevent the spread of decay into the wood. Flush cuts are harder for the tree to close and make it more likely that decay will spread beyond the wound.

Black pruning sealer painted over a recent pruning cut on a tree.
Pruning sealers (wound dressings)

Commonly believed to help trees heal and minimize sap loss, pruning sealers actually interfere with a tree’s natural ability to close wounds. They can also trap moisture inside the cut, which promotes decay. Trees will naturally form a callus over pruning cuts and do not need any assistance to close their wounds.

 

Wondering what to do instead?

Check out our tips for pruning young trees, watch a recorded pruning webinar, or join us for one of our free workshops.