Tree work words: pruning, planting and soil

Pruning and planting words move between countries and between authors. Thinning means one thing to ISA, another to QTRA and a third to Penn State. This page lists what each named source says a word means, so a term heard on a job can be matched to a written definition.

Every meaning is written in our own words from the page named in its row. A word that only one of these pages defines is left out, and so are the words already on tree work words: tree biology and plant health and tree work words: saws and cutting. The full list is the tree work glossary.

Pruning words

Term	Meaning and source
Cleaning, cleaning out	ISA's owner page defines cleaning as taking dead, dying, diseased, weakly attached and low-vigor branches out of the crown. QTRA's entry, cleaning out, lists dead, crossing, weak and damaged branches and adds the condition that the tree's overall look is not spoiled. Source: ISA TreesAreGood.org, Pruning Trees; QTRA, Glossary of Arboricultural Terms
Raising, crown lifting	ISA says raising takes off the lower branches to make room for buildings, vehicles, people on foot and views. QTRA calls the same kind of job crown lifting and words it as removing limbs and small branches up to a set height above the ground. Source: ISA TreesAreGood.org, Pruning Trees; QTRA, Glossary of Arboricultural Terms
Reduction, crown reduction	ISA says reduction makes a tree smaller, often for utility line clearance, by cutting leaders and branch ends back to side branches large enough to take over, at least one third the diameter of the stem cut. QTRA's crown reduction is a set cut in crown size that keeps the natural shape as far as possible. Penn State files the same aim under size management. Source: ISA TreesAreGood.org, Pruning Trees; QTRA, Glossary of Arboricultural Terms; Penn State Extension, Pruning Landscape Trees
Reduction cut	Penn State's name for a cut that shortens a limb back to a side branch big enough to carry on growing it. It gives the same one third rule of thumb that ISA gives for reduction, and adds an example: a 3 inch limb goes back to a side branch of at least 1 inch. Penn State says it was once called cutting to a lateral. Source: Penn State Extension, Pruning Landscape Trees; ISA TreesAreGood.org, Pruning Trees
Branch removal cut	Penn State's name for taking a branch off at its point of origin while the branch collar and branch bark ridge stay. Penn State says it was previously called a thinning cut. The Arboricultural Association describes the final cut of a branch removal as running from the branch bark ridge out to the collar. Source: Penn State Extension, Pruning Landscape Trees; Arboricultural Association, Guide to Tree Pruning
Thinning, crown thinning, reducing crown density	The three sources use the word differently. ISA says thinning is reducing the density of foliage at the edge of the crown to let wind or light through. QTRA's crown thinning removes a share of the secondary branches through the whole crown for an even spread of foliage. Penn State says the objective it calls reducing crown density was formerly called thinning, and that its branch removal cut used to be the thinning cut. Source: ISA TreesAreGood.org, Pruning Trees; QTRA, Glossary of Arboricultural Terms; Penn State Extension, Pruning Landscape Trees
Heading cut, heading	Penn State says a heading cut takes a branch or stem off between nodes, leaving a stub, back to a bud or to a live branch usually under one third the diameter of the piece removed. Washington State's vocabulary words heading as cutting back to buds, stubs or laterals too small to take over as leader, and adds cutting an older stem back to a stub to meet a structural aim. Source: Penn State Extension, Pruning Landscape Trees; Washington State University, Woody Plant Vocabulary
Topping	Each source words it differently. ISA says topping is the indiscriminate cutting of branches to stubs or to laterals too small to take over. Penn State says it is cutting down tree size without regard to long-term health or structure, and says it only becomes appropriate when taking a tree down in sections. Washington State calls it an inappropriate technique that cuts a tree back to a set crown limit. QTRA words it as removing the crown or most of it. A fifth meaning, felling aloft, is on tree work words: saws and cutting. Source: ISA TreesAreGood.org, Pruning Trees; Penn State Extension, Pruning Landscape Trees; Washington State University, Woody Plant Vocabulary; QTRA, Glossary of Arboricultural Terms
Flush cut	QTRA defines it as a pruning cut that removes part of the branch bark ridge, the branch collar or both. Penn State lists cuts placed just outside the branch collar, not flush cuts, among the signs it gives of proper work. Source: QTRA, Glossary of Arboricultural Terms; Penn State Extension, Pruning Landscape Trees
Final cut	The last cut that frees a branch. The Arboricultural Association puts it at the line from the branch bark ridge to the collar and says the British Standard for tree work gives the final cut a diameter of no more than one third of the parent branch. Penn State words the placement as just outside the branch collar. Source: Arboricultural Association, Guide to Tree Pruning; Penn State Extension, Pruning Landscape Trees
Structural pruning	ISA calls it essential in building a strong structure and good form in a young tree, with the aim of improving structure. Penn State describes improving structure as shaping the orientation, spacing, growth rate and attachment strength of branches and their final size. Source: ISA TreesAreGood.org, Pruning Trees; Penn State Extension, Pruning Landscape Trees
Temporary branches	Washington State defines them as branches, usually the lower ones, left in place in structural pruning of a young tree and removed later when the permanent framework is formed. Penn State says lower branches are left for the first two years to feed growth of the roots, trunk caliper and branches. Source: Washington State University, Woody Plant Vocabulary; Penn State Extension, Pruning Landscape Trees
Lateral	A side branch that sits under a larger one. Washington State calls it a secondary or subordinate branch or root. QTRA calls it a second order branch that carries sub-laterals. Penn State's reduction cut is made back to one. Source: Washington State University, Woody Plant Vocabulary; QTRA, Glossary of Arboricultural Terms; Penn State Extension, Pruning Landscape Trees
Node, internode	Washington State defines a node as the slightly swollen part of a stem where leaves and buds arise, and the internode as the stem between two nodes. QTRA's entry for internode agrees and adds that a length of stem bearing nodes but no branches is not an internode. Penn State places a heading cut between nodes. Source: Washington State University, Woody Plant Vocabulary; QTRA, Glossary of Arboricultural Terms; Penn State Extension, Pruning Landscape Trees
Watersprout, sucker	Washington State defines a watersprout as an upright epicormic shoot from a trunk or branch above the root graft or soil line, and says calling it a sucker is incorrect. Penn State says many weakly attached water sprouts grow from the wounds of a topped tree, and separately mentions suckers at the base of a young tree. QTRA's word for a shoot from a dormant or adventitious bud is epicormic. Source: Washington State University, Woody Plant Vocabulary; Penn State Extension, Pruning Landscape Trees; QTRA, Glossary of Arboricultural Terms
Wound dressing	QTRA defines it as sealants and other materials put over a wound in the hope of guarding against drying out and infection, and says they have proven value only against fresh wound parasites. Penn State lists cut surfaces left untreated by dressing or tree paint among the signs of proper pruning, because it says they can injure trees. Source: QTRA, Glossary of Arboricultural Terms; Penn State Extension, Pruning Landscape Trees

Planting and soil words

Term	Meaning and source
Root flare, trunk flare	University of Illinois Extension defines the flare as the part of the trunk where it starts to taper out as trunk tissue turns into root tissue. It says the flare is commonly buried in the pot or root ball. Colorado State Forest Service measures the planting depth from the bottom of the root ball up to the flare and says the flare sits 1 to 2 inches above ground level. Maryland's mulch page shows a mulched tree with the root flare visible. Source: University of Illinois Extension, Tree and Shrub Planting Guide; Colorado State Forest Service, How to Properly Plant a Tree, part 2; University of Maryland Extension, Excess Mulch Problems
Root ball	Washington State defines it as the soil holding all of the roots of a containerized plant, or a part of the roots of a balled and burlapped one, that move with the plant. Illinois Extension says the depth of the root ball on balled and burlapped stock can mislead on where the flare is. Source: Washington State University, Woody Plant Vocabulary; University of Illinois Extension, Tree and Shrub Planting Guide
Balled and burlapped, container grown, containerized, bare root	Washington State defines four ways stock is supplied. Balled and burlapped plants are dug with roots and soil wrapped in burlap or similar fabric. Container grown plants were grown in a container. Containerized plants were field grown, put in a container for a time and sold as potted, a term that leaves out plants first grown in a container. Bare root plants are dug with no soil on the roots. Illinois Extension groups potted and balled and burlapped trees together. Source: Washington State University, Woody Plant Vocabulary; University of Illinois Extension, Tree and Shrub Planting Guide
Transplant shock	Washington State defines it as plant stress after transplanting, with reduced growth, wilting, dropping foliage or death. Illinois Extension says trees and shrubs are in shock for several seasons, larger plants for longer, up to three years for most potted or balled and burlapped trees. Source: Washington State University, Woody Plant Vocabulary; University of Illinois Extension, Tree and Shrub Planting Guide
Staking, guying	Washington State defines staking as supporting a tree with stakes and ties, usually a new planting. Colorado State Forest Service names three reasons given for staking after planting: windy sites, activity near people and a tree that cannot hold its own weight, and says stakes stay in for one growing season. QTRA's guying is cable support for a tree whose anchorage is temporarily inadequate. Source: Washington State University, Woody Plant Vocabulary; Colorado State Forest Service, How to Properly Plant a Tree, part 2; QTRA, Glossary of Arboricultural Terms
Mulch	QTRA defines mulch as material laid over the rooting area to help hold moisture, organic or a sheet of plastic or other artificial material. Maryland Extension lists its uses as holding soil moisture, evening out soil temperature, protecting roots, cutting weeds and guarding the trunk from mowers. The sources give different depths: Maryland says organic mulch should not exceed 3 inches, Colorado State says no more than 3 to 4 inches, and Illinois Extension gives a layer of 2 to 4 inches. More on depth is on mulch depth and volcanoes. Source: QTRA, Glossary of Arboricultural Terms; University of Maryland Extension, Excess Mulch Problems; Colorado State Forest Service, How to Properly Plant a Tree, part 2; University of Illinois Extension, Tree and Shrub Planting Guide
Mulch volcano	Maryland Extension's photo caption uses the word for mulch placed wrongly against the trunk. Its text says mulch piled on trunks keeps the bark moist, which causes decay and a possible way in for disease and insects, and says to keep mulch 3 inches off the bark. Illinois Extension says not to mound mulch up around the trunk, and Colorado State says mulch is kept off the top of the root ball. Source: University of Maryland Extension, Excess Mulch Problems; University of Illinois Extension, Tree and Shrub Planting Guide; Colorado State Forest Service, How to Properly Plant a Tree, part 2
Soil compaction	Maryland Extension defines it as soil particles forced closer together, reducing pore space. It lists heavy foot traffic, wet soil being worked, construction machinery and parked vehicles as causes. The National Park Service describes repeated foot or equipment traffic reducing pore space and limiting the movement of air and water. Source: University of Maryland Extension, Problems Caused by Compacted Soil; US National Park Service, Relieving Compaction around Tree Roots
Pore space	The room between soil particles. Maryland Extension says it lets air and water move and lets roots grow. The National Park Service says compaction limits air and water by reducing it. Source: University of Maryland Extension, Problems Caused by Compacted Soil; US National Park Service, Relieving Compaction around Tree Roots
Air spade (air-powered excavation spade)	The National Park Service describes a hand-held tool with an air jet, run from a tow-behind compressor, that loosens soil without damaging roots and is used for radial trenching and vertical mulching. Maryland Extension says arborists sometimes use an air spade to fracture compacted soil without removing it, often in pie slices under the tree. Source: US National Park Service, Relieving Compaction around Tree Roots; University of Maryland Extension, Problems Caused by Compacted Soil
Dieback	QTRA defines it as the death of parts of a woody plant starting at shoot tips or root tips. The National Park Service says canopy dieback can be a sign of compaction around the root zone, and Maryland Extension lists dieback among the signs of a tree in decline from compacted soil. Source: QTRA, Glossary of Arboricultural Terms; US National Park Service, Relieving Compaction around Tree Roots; University of Maryland Extension, Problems Caused by Compacted Soil

Reading these sources

ISA's TreesAreGood.org page and Penn State Extension write for American tree owners, and Penn State refers to the ANSI A300 pruning standard for its objectives. The Arboricultural Association and QTRA write from the United Kingdom, and the Association quotes British Standard 3998 for the one third rule on the final cut. Washington State's vocabulary is a list of woody plant terms.

The planting rows rest on University extension and state forest service pages from Colorado, Illinois and Maryland, plus a National Park Service article. They describe how the words are used on those pages, not a planting specification. The standards that set specifications are on planting and soil standards and pruning standards.

Tree work words: pruning, planting and soil

Pruning words

Planting and soil words

Reading these sources

Sources