Lion-Tail Pruning

Lion tail pruning is more subtle than Topping, but can be just as damaging to the integrity of the tree.  This is when all the interior branches are pruned off the limbs leaving only the terminal leaves (like the tuff of the lion's tail.)  This has two results
  1. The tree again experiences malnutrition by losing substantial numbers of leaves that are exposed to sunlight, and its growth is forced out exclusively to the tip of the branch.  Thus, branches become abnormally elongated. Sometimes the tree get "sun burn" where the bark is damaged and splits without shade.
  2. Branches lose their normal taper because they require nutrition along their length to thicken and strengthen.  These limbs are thinned and weakened and form a long lever for breakage with loading, like ice or wind catching the leaf tuffs at the ends. In addition, cavities typically form along the branch since the interior removals often scalp the bark and the tree heals lateral cuts poorly.
It is harder to understand why people do lion-tailing; somehow they feel the tree will be neater or less likely to shed small dead wood and twigs if the limbs are cleaned off, not realizing that every leaf feeds the tree and preserves its structural integrity.  People feel their trees look well-cared for when they clean out all the interior growth, like edging the lawn.   Again, trees will try to make up the loss of interior leaves and often re-initiate latent buds, even on large branches and trunks, a phenomenon called "epicormal sprouting".  A tree can recover from lion-tailing if the sprouts are allowed to develop into branches and then reduced slightly and spaced along the branch.  Often pruning off these interior branches creates splits along the branch and rots begins.

This sugar maple had extensive and repeated lion tail pruning.
 Notice the extreme length and unnatural thinness of its branches with loss of normal taper. There is a long slit cavity on the remaining branch.  The tree broke apart despite extensive cabling to try to provide support to the branches and to prevent breakage.  The broken branch on the right was so long that it extended well past the corner of the house and half way up the driveway on the next house.

This  tree was otherwise healthy and sound, but became a complete loss despite expensive cabling because of the pruning malpractice that weakened its limbs
against loading.

The form of this oak has been damaged by lion tailing.
It has initiated new upright branching
 on the upper branch.

The natural sequence for oaks is for shorter lower branches to be shaded out under the expansion of the upper canopy and to spontaneously shed at a small diameter, so the tree "self-prunes".  The shaded lower branches normally are suppressed and stop growing.  Lion-tailing defeats this natural process by forcing growth outward into the sun.  This destroys the natural habit of the tree and makes these abnormal branches much weaker.

Increased hazard from lion tailing.
This ash has developed thin and elongated major trunk divisions  with a few feeble suckers along its attenuated divisions.  Ashes tend to lose dead wood, and the extended branches are now more dangerous than any smaller breakage would be.


Many tree workers knock on the door after storms and offer cheap services to "clean up your tree" but you need to understand what makes your trees healthier over the long run.