The general public uses terms like cutting, trimming, or shaping interchangeably when referring to tree care. Within the professional field of arboriculture, however, a specific vocabulary defines the precise actions performed on a tree. This terminology reflects the scientific objective and method behind each cut. Understanding these professional names ensures a tree receives proper, health-focused care rather than arbitrary alteration.
Pruning Versus Trimming: Defining the Difference
The most common point of confusion involves the terms “pruning” and “trimming.” Trimming is generally the practice of cutting back overgrown plants for aesthetic purposes or to maintain a specific shape, often applied to hedges, shrubs, or smaller ornamentals. This action focuses on tidiness and curb appeal.
Pruning, in contrast, is the science-based, selective removal of specific plant parts, such as branches or roots, to improve the tree’s health, structure, and safety. The goal is not cosmetic but to direct growth, mitigate structural defects, and remove unhealthy tissue. For mature trees, “pruning” is the accepted term, distinguishing it as a strategic intervention.
Essential Pruning Techniques and Terminology
Professional tree work is defined by the specific goal of the cuts made, leading to distinct names for accepted practices.
Crown Thinning
Crown Thinning involves the selective removal of smaller, interior branches uniformly throughout the canopy. This technique does not reduce the tree’s overall size but improves light penetration and air movement within the crown. Increased airflow helps reduce the risk of disease by minimizing prolonged moisture buildup on foliage.
Crown Reduction
Crown Reduction is used when the height or spread of a tree must be decreased, often to clear utility lines or structures. This practice requires making cuts back to a lateral branch large enough to assume the terminal role, ideally at least one-third the diameter of the removed limb. The purpose is to reduce size while attempting to maintain the tree’s natural shape and structural integrity.
Cleaning or Deadwooding
Cleaning or Deadwooding is performed solely for the health and safety of the tree. This involves removing dead, diseased, or broken branches from the crown. Removing this material eliminates potential entry points for pests and pathogens and reduces the hazard of falling limbs. Proper cuts are made just outside the branch collar to allow the tree’s natural compartmentalization process to seal the wound effectively.
The Misidentified Practice of Tree Topping
The harmful practice the public sometimes refers to as “cutting back hard” is professionally known as Topping, and it is universally condemned by arborists. Topping, sometimes called Hat-racking, involves the indiscriminate removal of large branches and main stems back to stubs. This process typically removes between 50 and 100 percent of the leaf-bearing crown in a single session, disregarding the tree’s natural structure or biology.
This drastic removal of foliage immediately sends the tree into shock, reducing its ability to produce food and depleting stored energy reserves. The tree responds by quickly producing dense, upright shoots known as water sprouts or suckers from the stubbed cuts. These sprouts are poorly attached and structurally weak, creating a future hazard more likely to break during high winds or storms.
The large, open wounds left by topping rarely heal properly and become prime entry points for decay organisms, insects, and disease. This decay weakens the main structure of the tree, making it more hazardous than before the procedure. Unlike the controlled cuts of crown reduction, topping destroys the tree’s natural form and significantly reduces its lifespan.