Pollarding is an ancient, specialized pruning technique that has been used for centuries, particularly in Europe, to manage tree size and harvest wood products. The technique often receives a bad reputation because the term is frequently—and incorrectly—used to describe a destructive practice known as tree topping.
The Definition and Technique of Proper Pollarding
Proper pollarding is a controlled system that must begin when a tree is young, establishing a permanent framework for future growth management. This initial cut removes the central leader and upper branches to a chosen height, which is usually above the reach of grazing animals. The technique is primarily used on deciduous species like London plane, lime, and willow, which respond well to heavy pruning by producing vigorous new growth.
The defining feature of a correctly pollarded tree is the formation of specialized, swollen structures called pollard heads or knuckles. These knuckles are created over years as the tree repeatedly compartmentalizes the small wounds from cyclical pruning. All subsequent pruning cuts are made precisely at the point of origin, just above these established knuckles, which serve as the source for the next season’s growth. This continuous, cyclical maintenance, often performed annually or biennially, ensures the wounds remain small and heal quickly, supporting the tree’s long-term vitality.
Why Arborists Utilize Pollarding
Arborists utilize pollarding for several legitimate reasons, primarily centered on size control and safety in congested urban environments. The practice prevents trees from outgrowing their allotted space, which is especially important where tree growth must be strictly managed near buildings, sidewalks, and roadways.
When maintained correctly, pollarding promotes a dense, predictable crown of new, smaller branches, which helps maintain safety clearances. This dense new growth, known as epicormic shoots, is contained within a stable, structurally sound framework of established branches. By keeping the tree at a reduced, manageable size, the technique can also extend the life of certain species by reducing the risk of structural failure associated with overly large limbs in confined settings.
The Difference Between Pollarding and Tree Topping
Topping involves the indiscriminate, severe reduction of a tree’s crown by cutting large branches back to stubs without regard for branch collars or lateral buds. This practice is not a controlled system and is performed on trees of any age, typically in a misguided effort to reduce height quickly.
The consequences of topping are severe because the large, unhealable wounds invite decay and disease into the major structural wood of the tree. By removing a large portion of the canopy, topping also severely limits the tree’s ability to photosynthesize, leading to a state of starvation and intense stress. The tree’s survival response is to rapidly produce numerous weak, fast-growing shoots, often called water sprouts, from dormant buds near the cut ends.
These water sprouts are only superficially attached to the stubs, lacking the strong branch collar connection of naturally developed limbs. This results in an extremely high risk of structural failure, as the rapidly growing, weakly attached branches are prone to breaking off in high winds or during storms. While pollarding is a systematic, continuous process creating controlled small wounds on young trees, topping is a damaging, one-time event on mature trees that results in large, non-healing wounds and dangerous regrowth.