Pruning involves the selective removal of branches to improve a tree’s health, structure, and appearance. While proper pruning supports long-term tree integrity, “lion tailing” is a specific, damaging technique that undermines tree health. Arborists consider this method malpractice because it involves the aggressive removal of a tree’s interior growth. Understanding this practice is the first step in preventing serious harm to the trees in your landscape.
Identifying Lion Tailing
Lion tailing is a form of over-pruning resulting in a distinctive, unnatural visual appearance. The practice involves stripping away most of the inner lateral branches and foliage along a main limb. This leaves a long, bare stretch of branch terminating in a dense clump, or tuft, of leaves at the very end, resembling a lion’s tail.
The motivation for this aggressive thinning is often misguided; inexperienced trimmers may believe it reduces the tree’s weight or increases light penetration below. Instead of selective thinning throughout the canopy, they remove the interior structure. This results in a canopy that appears hollowed out or “gutted” from the inside, disrupting the tree’s natural balance and architecture.
Why This Pruning Technique Harms Trees
Lion tailing causes structural damage that compromises a tree’s ability to withstand environmental stress. Removing the interior foliage concentrates the limb’s weight far out on the branch tip. This shift in weight distribution increases the leverage on the branch union, making the limbs highly susceptible to breakage during high winds or heavy snow loads.
The loss of inner branches eliminates the natural “mass dampening” effect that evenly distributed foliage provides. Instead of wind energy being absorbed and dissipated by many small branches, the force is caught by the dense tuft at the end, creating a “wind sail” effect. This causes the end-heavy branches to whip violently, placing excessive stress on the wood and increasing the likelihood of catastrophic limb failure.
Lion tailing also severely impacts the tree’s ability to produce energy through photosynthesis. The removal of a large volume of the interior crown drastically reduces the tree’s total photosynthetic surface area. Interior leaves are particularly important because they are often the main food producers during the hottest parts of the day when the outer canopy leaves may become too stressed by heat and light to function efficiently.
The sudden exposure of previously shaded bark to direct sunlight creates another serious problem known as sun scald. The bark on the inner branches and the trunk, which was protected by the interior foliage, can suffer thermal damage and cracking when rapidly exposed to intense sun. This damage weakens the tree and creates open wounds that serve as easy entry points for wood-boring insects, fungi, and various diseases.
Repairing and Avoiding Lion Tailing Damage
Preventing lion tailing requires understanding proper structural thinning, which is the selective removal of small branches throughout the entire canopy. Arborists recommend never removing more than 25 to 30 percent of a tree’s live crown in a single year to maintain its health and structural integrity. The goal is to allow light and air to filter through the canopy, not to hollow it out.
If a tree has been subjected to lion tailing, correction requires a long-term, gradual approach. The tree often responds to the stress by producing numerous weak, fast-growing shoots, known as epicormic sprouts, along the bare sections of the branch. These sprouts should be allowed to grow for a few seasons, as they are the tree’s attempt to replace the lost foliage and restore photosynthetic capacity.
Corrective pruning involves selectively thinning these new sprouts and shortening the ends of over-elongated branches in subsequent years. This process requires patience, as the goal is to encourage permanent, well-spaced branches along the bare sections to redistribute weight toward the trunk. For severe cases, consulting a certified arborist is necessary to establish a multi-year pruning plan and determine if the weakest limbs should be removed for safety.