This is the glossary page listing many common terms

(as defined by TheGoodTreeCo.)

Air spade is a specialist excavation tool that uses compressed air to remove and break up soil with minimal damage to roots and underground utilities. It can be used for a variety of reasons including the alleviation of compaction , soil improvement, root inspection and root location. Contact us for more info if you think it can help you.

Arboriculture the practice and study of the care of trees in the landscape.

Arboricultural Association Approved Contractor see FAQs

Arborist professional who possesses the technical competence gained through experience and related training to provide for or supervise the management of trees in residential, commercial and public landscapes

Arisings all debris resulting from treeworks

Bracing See Cable bracing

Branchwood/Brushwood Branches and foliage removed from a tree, up to approx. 150mm (6)

BS3998 British Standard Recommendations for Tree Work

BS5837 British Standard Recommendations for Trees in Relation to Construction

Buttress roots Roots at the base of the trunk; trunk flare

Cable bracing Installation of hardware or synthetic rope in a tree to provide supplemental support to weak branches or branch unions.

Canopy See Crown

Cavity Hole in a tree resulting from decay or damage

Conservation Area A protection order that means the LPA must be informed of any works to trees with a diameter over 75mm – there are some exemptions from this. The LPA then has 6 weeks in which to place a TPO should they object to the proposals. Heavy fines can be enforced should this process be circumvented

Coppice The entire removal of the growth of a tree to a stump in order that the tree will re-generate. A traditional practice used to produce straight stems of wood in a regular cycle. Also used to create vigorous re-growth or reform certain growth forms. Only appropriate for certain species and ages of tree

Cordwood Timber greater than 150mm (6) in diameter and smaller than approx. 300mm (1ft). If cordwood is to be left on site it is generally left in 600 900mm (3-4ft) lengths unless otherwise specified

Coronet cut A finished cut on a tree used to mimic natural tearing. Mainly used on wildlife sites

Crown That part of a tree that is composed of the branches and the foliage

Crown clean Removal of dead, dying, diseased, crossing, epicormic and obviously hazardous branches

Deadwood This wood is often removed due to safety concerns or in order to create/maintain a feature tree. However it is important for the sustainability of wildlife. Where suitable it may be left on site in eco-piles

Dieback Condition in which the ends of the branches are dying

Dismantling a method used to remove a tree in a confined area, piece by piece

Eco-pile Over zealous removal of all deadwood and arisings can be detrimental to wildlife. In appropriate circumstances it is suggested that arisings are left neatly stacked, often hidden from view, in order to help maintain and encourage wildlife.

Epicormic Small re-growth often stimulated through stress and/or over zealous pruning

Felling a method used to remove a tree by cutting at the base and directing the whole tree to fall in a specific area

Formative prune Pruning young trees to create a desired form or shape. The aim is most often to produce a tree that in maturity will be free from major physical weaknesses.

Habit The shape of the tree

Hazard beam A large branch that shows signs of potential and probable failure.

Included bark Bark that is pushed inside a developing fork, causing a weakened structure

ISA Certified Arborist certified arborists undergo an examination and are required to keep up to date with the latest practices, being re-certified every 3 years. Jonathan Finlow, owner of TheGoodTreeCompany has been a Certified Arborist since 1999. See

Leader The main upright stem or shoot at the centre of a tree

Lift The removal of branches either in part or entirely to raise the height of the lower crown. This practice can greatly increase light as well as improving sightlines and views. Lifting may also be effective in helping create a feature of the bark or stem of a tree from what may have been an undefined form

Lion tailing Poor example of thinning where shoots along the entire length of a branch are removed leaving all the foliage at the end of the branch. This practice increases the chance of branch failure due to the exaggerated weighting and results in profuse epicormic regrowth

LPA Local Planning Authority

Pollard Pruning technique that begins on young trees, in which the tree crown is regularly cut back to bare branches. Used to maintain trees at a certain height and shape but must be begun when the tree is young. Only suitable for certain species

Pruning cutting away unwanted or damaged parts of a plant

Reaction wood Wood formed, often as strengthening material, on a weakened part of the tree

Reduction Method of reducing the height and most often also the spread of a tree by cutting branches to laterals that are large enough to support the growth of the limb. The aim is most usually to leave a natural shape

Re-shape as it sounds, using different pruning methods, e.g. selective reduction

Ringwood Timber larger than approx. 300mm (1ft) in diameter. If this wood is to be left on site it is usually done so in lengths that are able to be split with an axe (approx. 300mm length and less)

Sail Area the area of the tree that is affected by the wind

Scaffold branchesThe main structural branches within the crown of a tree

Selective reduction This is used where an overall reduction is unnecessary or inappropriate. The overall effect is usually to bring in branches that are outside the uniformity of the crown or those that are causing particular problems or concern

Stem The trunk of the tree

Sucker Shoot arising from the roots

Thinning The removal of small branch growth from throughout the crown of a tree. This technique is used to provide air/light/wind penetration through the crown of a tree and to lighten the weight of the branches whilst maintaining the essential shape of the tree. See also Lion Tailing

TPO Tree Preservation Order. Proposed works to a tree with a TPO on it must be submitted to the LPA. They will then usually take up to 8 weeks in which to reach a decision. There are some exemptions from this. Heavy fines can be incurred if this procedure is not followed

Tracery Used in reference to the branches. The pattern/structure of the trees branches.

Tree surgeon see arborist, although some tree care professionals would make the distinction that an arborist has spent more time studying and understanding. I make no real distinction, it all becomes confusing and possibly a little pretentious. I think you have good tree surgeons, bad tree surgeons and many shades of tree surgeon/arborist/smarborist.

Tree surgery generally interpreted as the practical craft within arboriculture, although, see tree surgeon above

Whorl A group of branches arising from the same level on a stem

Windthrow the failure of an entire tree due to the action of the wind

Woodchip A chipping machine is used to process branchwood. This creates woodchip that is used in suppressing weeds, covering pathways , creating a feature where once there may have been poor grass/soil cover and many other uses. Please ask for details. It is usually possible to leave resultant woodchip on site