Tree Terms

• Branch collar: “area where a branch joins another branch or trunk created by the overlapping xylem tissues” (this area must not be flush cut)
• Branch bark ridge: “top area of a tree’s crotch where the growth and development of the two adjoining limbs push the bark into a ridge” (this indicates roughly the spot at which a pruning cut should be made)
• Branch protection zone: “tissues inside the trunk or parent branch at the base of a subordinate branch that protect against the spread of decay” (pruning must not cut into this area)
• Lateral branches: “secondary or subordinate branches”
• Scaffold branches: “the permanent or structural branches of a tree”
• Apical dominance: “condition in which the terminal bud inhibits the growth and development of lateral buds on the same stem” (this is usually a good thing – it is how the tree grows naturally)
• Codominant branches: “forked branches of nearly the same size in diameter and lacking a normal branch union” (usually the smaller or weaker would be removed – one of them should always be removed)
• Included bark: “bark that becomes embedded in a crotch between branch and trunk or between codominant stems and causes a weak structure” (included bark crotches are the most likely to break; removing one of the codominants is a feature of proper pruning)
• Leader: “the primary shoot or terminal trunk of a tree” (seldom should the leader be cut off – it is sometimes legitimate to reduce the leader, however)
• Permanent branches: “branches that will be left in place, often forming the initial scaffold framework of a tree”
• Temporary branches: “branches left in place when training young trees; such branches will be removed later”
• Waterspouts: “an upright, adventitious shoot arising from the trunk or branches or a plant; although incorrect, it is also called a sucker” (a sucker grows out of the ground rather than the trunk or a branch)
• Crown cleaning: “removal of waterspouts and dead, dying, diseased, crossing, and hazardous branches from a tree” (this is difficult and time-consuming)
• Structural pruning: “pruning to establish a strong branch scaffold system” (usually the most important pruning procedure)
• Raising: “removing lower limbs from a tree to provide clearance”
• Reduction: “pruning to decrease height and/or spread of a branch or crown” (must be done carefully – have to avoid ‘”heading back” or “topping”)
• Heading back or topping: “cutting limbs back to buds, stubs, or lateral branches not large enough to assume topical dominance” (nearly always is incorrect – but commonly practiced by the unknowing)
• Lion tailing: “poor pruning practice in which limbs are thinned from the inside of the crown to a clump of terminal foliage” (it is easier to prune closer to the trunk than to the tips of branches – but lion tailing causes limb breakage)
• Thinning: “selective removal of unwanted branches and limbs to provide light or air penetration through the tree or to lighten the weight of the remaining branches”
• Restoration: “pruning to improve the structure, form and appearance of trees that have been severely headed, vandalized, or damaged” (the most difficult of all pruning tasks; a certified arborist should always be in charge of restoration pruning)
• Pollarding: “a specialty pruning technique used on large-maturing trees that results in the development of callus at the end of the cut branches” (often used in Europe and anyplace where space is severely limited)
• Espalier: “specialized technique of pruning and training plants to grow within a two dimensional plane” (an example would be training a pear tree to grow flat against a wall)
• Vista pruning: “selective pruning to allow a view from a predetermined point” (sometimes employed for “dish” reception)