Amenity Value: The environmental and landscape benefits of trees as opposed to their commercial value for timber.
Arboriculture: Management of individual trees or groups of trees primarily for their amenity value.
Bracing: Bracing is a term used to describe the strengthening or supporting of a tree by means of cables, rods, webbing or similar.
Branch bark ridge and collar: More noticeable on some species than others are branch bark ridges, which is protruding bark at the top of a junction (crotch) of two branches; and continues downward from crotch. Also more noticeable on some species than others is the branch collar; a swelling at the base of the branch. Neither the branch bark ridge nor collar should be cut.
Callus: Scar tissue laid down by the tree in order to cover and protect a wound, eg a pruning wound.
Cavity work: Removal of material from cavities and drainage of cavities achieved by drilling through living wood. Modern research indicates this should not normally be carried out.
Coppicing: The cutting down of a tree within 300 mm (12 in) of the ground at regular intervals (typically on a one to five year rotation). Traditionally applied to certain species such as Ash, Hazel and Sweet Chestnut to provide stakes, poles, firewood etc.
Crown: The section of the tree formed by its branches and usually starting above its stem.
Crown Reduction: Crown reduction is used to reduce the height and/or spread of the crown/canopy of the tree. We achieve this by removing the tips of the branches at suitable growth points, whilst ensuring to maintain the tree(s) natural shape.
Crown Thinning: Crown thinning is when a small percentage of secondary and small live branches are removed throughout the crown of the tree. We typically only apply this method to broad-leaved species. It helps to improve light levels, reduce wind resistance and balance branch structure, whilst retaining the tree’s original size and shape.
Crown Raising: Crown raising/lifting involves directly removing low branches or parts of branches that may be causing obstruction. Large branches growing directly from tree trunk should not be removed as they could damage the tree permanently. We use this technique to help improve light penetration and provide adequate access for vehicles (5.2M) and pedestrians (2.5M) in accordance to UK common practices.
Deadwood Management (Crown cleaning): Deadwood Management involves removing dead, dying, diseased, broken, weakly attached and split branches from the crown of the tree. Particularly when they are deemed a health and safety risk. We also remove climbing plants such as ivy that can be damaging to the tree.
Dead, Dying Dangerous or a Nuisance: The catch-all phrase describing the conditions of trees to which protection afforded by Tree Preservation Orders or Conservation Areas does not apply. Legal definitions are the subject of much debate, sometimes through the courts, tree inspections by Colin White Tree Surgeons can give advice on such matters.
Decline: When a tree exhibits signs of a lack of vigour and progressing towards its death.
Dieback: Tips of branches exhibit no signs of life. As decline progresses so more branches are affected and to a greater extent.
Dormant: The inactive condition of a tree, usually during the coldest months of the year when there is little or no growth and leaves of deciduous trees have been shed.
Drop Crotching: Shortening branches by pruning off the end back to a lateral branch which is at least 1/3 diameter of the removed branch.
Fertilising: The application of a substance usually to the tree’s rooting area (and occasionally to the tree) to promote tree growth or reverse or reduce decline.
Flush Cut: A bad practice of removing a branch by cutting very close to the branch to be retained, cutting through the branch bark ridge and/or collar, thereby reducing the ability of the tree to callus.
Forked growth (Co-dominant stems): The development of two or more leading shoots of roughly equal size and vigour competing with each other for dominance.
Formative pruning: Pruning during the early years of a tree’s growth to establish the desired form and/or correct defects or weaknesses.
Fungi/Fruiting bodies: Any spore-bearing structure on a stalk (like a toadstool) or attached directly to the tree (a ‘bracket’ fungus). Note: some are harmful (cause disease – pathogenic), some are harmless (living on material already dead – saprophytic) and some are beneficial (symbiotic).
Hanger: Dead branch fallen from the crown but caught by, and resting on, branches lower down.
Lopping and Topping: Generally regarded as outdated terminology but still part of Planning legislation. Lopping refers to the removal of large side branches (the making of vertical cuts) and topping refers to the removal of the head or crown of the tree (the making of horizontal cuts). Often used to describe crude, heavy-handed or inappropriate pruning.
Mature: Trees that have attained full size.
Painting or Sealing: A now uncommon and discredited practice of covering pruning cuts or other wounds with a bitumen-type substance. Research has demonstrated that this is not beneficial and may in fact be harmful to trees.
Pathogenic: Disease inducing – usually referring to fungal fruiting bodies.
Pollard: Traditionally and still commonly used this term describes the removal of all branches from the trunk. Mature trees that have not been pollarded before are generally not suitable candidates for pollarding due to the large wounds that such treatment produces which may jeopardise the long term future of the tree. A less frequently used definition can mean the regular (annual or biannual) pruning back of small branches to the same point resulting in the formation of a ‘pollard head’. Pollarded trees usually require regular treatment of re-growth. Pollarded trees are a common sight on French boulevards.
Root Protection Area (RPA): The RPA of a tree is the area around its base that contains sufficient rooting volume to ensure the survival of the tree in the event of nearby soil disturbance (as on a development site). The RPA is calculated using guidelines in BS 5837 (2005) Trees in relation to construction – Recommendations
Root pruning: The pruning back of root (similar to the pruning back of branches). This has the ability to affect tree stability so it is advisable to seek professional advice prior to attempting root pruning.
Senescence: The third phase of a tree’s life, after youth and maturity, when the leaf area of the crown tends to diminish. Veteran trees are generally senescent.
