Tree Care Glossary



3-POINT CUT

This basic technique is used for pruning all types of branches. Two initial cuts are made to remove the weight of the branch from the tree, followed by a clean, precise third (or finishing) cut.

ARBORIST

A professional trained in the care and maintenance of trees, shrubs and other woody plants. An arborist’s focus is on the health and safety of individual plants and trees in residential and commercial settings.

BARK TRACING

The practice of cutting away loose bark from around a tree wound. A sharp, sterilized knife is used to carefully remove the loose bark, allowing the damaged area to heal.

BRACING

The use of rods, clamps or other stabilizing materials to secure weaker limbs to a sturdier part of a tree, or to alter the direction of growth.

CABLING

The use of cables and bolts to connect weak limbs to each other and reduce movement. This is usually done to prevent wind damage in poorly-structured trees.

CALLUS

The tissue that forms around a tree wound through the natural healing process of the tree.

CANOPY

The extent of the outer layer of a tree’s leaves.

CLEARANCE PRUNING

Pruning to create an open area around a tree, often to make room for utility lines and poles. It may also be used to improve visibility or remove obstructions to traffic flow.

CRITICAL ROOT ZONE

The volume of roots necessary to sustain the life of a tree. This zone usually extends out to the drip line of the tree (the area beneath the outermost leaves of a tree).

CROWN ELEVATION

The removal of low-hanging limbs to clear space underneath the branches of a tree. This is usually done to clear walkways or drives, or to improve the line of sight.

CROWN REDUCTION

Selective pruning of limbs to reduce the height of a tree.

CROWN THINNING

Selective pruning of interior branches to improve air flow and light penetration.

DBH

This stands for Diameter at Breast Height (the diameter of most trees is usually measured at breast height, or 4.5' above the ground).

DECIDUOUS

Category of plants that lose their leaves annually.

DEFOLIATION

The process of losing leaves naturally, or due to pests, disease or drought.

DRIP LINE

The area directly beneath the outer circumference of a tree’s canopy (the outer layer of leaves). This area contains the vital rootlets of the tree’s root system.

EVERGREEN

Category of plants that retain foliage throughout the year.

FRUIT REDUCTION

Limiting the production of unwanted fruit on ornamental trees with a spray application.

FUNGICIDE

A chemical agent that destroys or inhibits the growth of harmful fungi.

HAZARD PRUNING

Pruning to reduce the chances of damage from dead, diseased or weakened branches falling from a tree.

INTEGRATED PEST MANAGEMENT

An environmentally sensitive approach to controlling pests in the landscape which focuses on prevention. This approach utilizes thorough inspection and identification before carefully deciding on the appropriate treatment, often limiting the use of pesticides.

LIGHTNING PROTECTION

Installation of a system designed to divert lightning safely into the ground, protecting a valuable tree from lightning damage.

MAINTENANCE PRUNING

Pruning that is done routinely to preserve the proper shape and size of a tree, improving its overall structure and health.

NEEDLE DROP

Loss of needles on evergreen trees. This may be a sign of pest or weather damage, but also occurs naturally as old needles are replaced by new ones.

ORNAMENTAL

Usually smaller-sized trees chosen for aesthetic characteristics such as flowers, dramatic leaf color, bark or decorative form.

PALM PRUNING

The removal of old, dead fronds and other non-essential plant parts that may be shed by a palm. This improves palm health and appearance while decreasing the risk of personal injury or property damage.

PLANT HEALTHCARE

This holistic approach to caring for plants addresses environmental conditions and cultural practices that impact their well-being.

RISK ASSESSMENT

Professional inspection and analysis of a tree’s condition to identify the risk of property or personal damage caused by tree failure.

ROOT BALL

The roots and surrounding soil at the base of a tree (visible when transporting a tree from a nursery to its planting site).

ROOT BARRIERS

Materials installed to direct tree roots away from a hardscaped area such as a sidewalk (to prevent damage that may be caused by root expansion).

ROOT COLLAR EXCAVATION

The removal of excess soil or mulch from around the base of a tree to correct either over-mulching or a tree that has been planted too deeply. This helps to prevent tree decline and reduces the chances of insect or disease damage.

ROOT FERTILIZING

Injection of essential nutrients directly into a tree’s root zone. Regular feeding provides trees with better resistance to disease, insects and drought while supplementing poor soil conditions.

ROOT PRUNING

The mechanical trimming of tree roots, usually to prevent root damage to surrounding structures.

ROOT ROT

Decay (or rotting) of tree roots, often caused by disease or overwatering.

SPECIMEN

This term usually applies to a unique or uncommon tree chosen for a high-visibility area.

SPRAYING

Common means of applying pesticides, fungicides and other treatments to trees.

STUMP GRINDING

The removal of a tree stump using a power grinder that cuts the remaining trunk and exposed roots into small wood chips.

SYSTEMIC INSECTICIDE

An insecticide that is absorbed by the root system of a plant, controlling the insect as it eats the plant.

TOPPING

An undesirable method of removing limbs to severely reduce a tree’s size (the top of the tree is literally removed). Topping is not a recommended pruning practice.

TREE CAVITY

An empty space in a trunk or large limb, usually caused by untreated bark damage that allows disease or insects to infect or enter a tree.

TREE REMOVAL

This is usually done when damage to surrounding plants or structures is a serious concern, or if a tree is no longer vital. Professional expertise is critical to the safe execution of this multi-step process, which includes limb removal, cutting down the main trunk and grinding out the stump.

TRUNK FLARE

The area at the base of a tree where the trunk broadens to form roots.

WATER SPROUT

An undesirable shoot or stem sprouting from the trunk of a tree or from an old branch, which goes on to produce inferior, weak branches. Sprouts are often removed through maintenance pruning.

YOUNG TREE PRUNING

Pruning in young trees that is done to define good branch structure, promoting and supporting the growth of a strong, balanced tree.

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