What is "lion tailing"?

Apr 13, 2024

“Lion tailing” is stripping out the interior growth on the inside of the tree canopy, leaving only a small amount of leaves at the end of the branch. This is a poor example of reducing crown density to increase light penetration to the ground below.

Sun scald, especially on red oaks, begins a stress spiral that leads to death. With the inner canopy stripped the tree is starved and has limited resources so the decay spreads and the branch dies or breaks. Then the branch under that one gets sun scald which creates a snowball effect that’s almost impossible to stop in many cases. Over pruning causes a lot of health issues for trees. — Tree with “lion tailing”. The interior canopy has been removed causing multiple stressors to the tree.

There is no response from the tree at the edges of where the bark is popping off which indicated there are multiple stressors affecting its health. With the tree being "lion tailed" it has been starved and doesn't have the resources to heal itself. — Close up view of same tree with sun scald damage.

Why is “Lion tailing” bad for trees?

Starves the Tree

Trees use their canopy and leaves to produce food via photosynthesis. Removing too many leaves will reduce the tree’s ability to make food. Hungry tree = sad tree
The inner leaves of the canopy are the main food producers for trees when temperatures rise because the leaves on the outer canopy get too hot and are unable to do the work. This is especially true in North Texas because of the extreme heat we experience during the summer.

Improperly pruned American Elm Tree with a broken branch after a storm

Same American Elm tree zoomed in on where the limb broke off.

Prone to Breakage

Lion tailing makes limbs more likely to break. We know this seems counterintuitive, but when all the weight is at the end of a limb or branch rather than spread across it increases the amount of force on the branch.
Mass Dampening is when the twigs and leaves in the tree canopy disburses the force of the wind. Mass damping reduces the chances of limb breaking.
The idea that stripping out the canopy so wind can move through it, has been proven to be wrong.

Decay

Sun scald is essentially a sunburn on tree bark. It happens when temperatures get too high and kill the exposed bark. When trees have been over trimmed and lion tailed sun scald on the branches leads to decay of the limbs making the tree less stable.
Sunscald is rarely seen in a forest but we often see it in our Urban setting in North Texas. We especially see it on over-trimmed red oaks and maples (trees with thinner bark).

Proper tree trimming requires education and skill to protect your trees from damage and costly mistakes. To avoid improper pruning use a certified arborist, and listen to their advice.

A correct tree trim reduces less canopy, and costs less.

At Texas Tree Surgeons, we love trees and our community. We believe that through education we can take better care of our urban forest. Trends are started in neighborhoods accidentally through misinformation. If you have any tree questions don’t hesitate to get in touch!

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