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A Guide to Tree & Hedge Work Terminology

Posted onApril 20, 2016

Tree surgery, as with any project, can feel confusing when you don’t know the correct terminology.

Here is a quick guide to some of the more common tree and hedge work terms.

Crown Lift

A crown lift is the complete removal of the lowest branches back to the main trunk and or the reducing back in length of the lowest branches, which increases the height of the main crown line above ground level. This is usually expressed in metres.

Crown Reduction/Reshape

This is the all round reduction of the crown size of the tree but not the tree’s overall height unless otherwise specified. Usually this kind of work is expressed as a percentage by the tree surgeon i.e. reduce crown by 20%. In some cases only a partial crown reduction is specified in order for the crown to clear a building, street furniture etc and this will be expressed in metres.

Clean Out Crown

This is the crown cleaning removal of dead-wood, dying, diseased, weak suppressed, split broken, hanging, crossing and rubbing branches and epicormic growth (small shoots emanating from the main trunk and stems) from the crown.

Crown Thin

Thinning the crown in tree surgery means removing all the branches as in ‘Cleaning out the Crown’ and the removal of further smaller diameter branches evenly throughout the crown in order to lessen the crown’s density and improve light through the tree. Crown thinning does not result in a major alteration in the outline of the tree and changes are again usually expressed in the form of a percentage by the tree surgeon.

Removal of Dead Wood

This is the removal of all major dead wood in the tree down to approx 3-4cms diameter.

Formative Prune

Minimal tree pruning of, usually, young trees to maintain optimum initial branch structure and the tree’s crown balance in order to pre-empt potential future problems.


This usually refers to hedging and shrubs both evergreen and deciduous and is the pruning back to flatten off or round off growth to contain the spread and maintain control/optimum visual appearance and shape.


Pollarding a tree means removing all the growth back to the main trunk or trunk knuckles unless otherwise specified. This helps to control growth and keep trees at a predetermined height.


Felling a tree is the complete removal of the tree as near to the ground or surrounding soil level as possible, leaving a stump. This usually involves the dismantling of the tree in sections. Usually a tree fell is the last resort before the tree surgeon considers all other options.

Grind Down Stump

Refers to a stump grind at or near ground level and is the mechanical grinding down of the stump to below ground level only. The tree’s radial root spread remains intact unless otherwise specified. Arisings are removed to leave area level.

Grind Out Stump

In some cases, usually with smaller, shallower stumps it can be possible to grind out the whole stump. On larger stumps the grinding of radial roots down to a certain diameter may be specified. Stump grinding is a specialised practice and is undertaken with a stump grinder and experienced tree surgeon.

Grub Out

This refers to the stump and roots of a tree and is the physical/manual digging out of a stump and it’s root system. This usually applies to smaller trees.

Winch Out

Refers to the stump and roots of a tree and is the physical/manual excavation of the area around the tree and stump. It includes the severance of major radial roots and the mechanical winching of the stump from the ground then the back filling of the area where possible to level it out. This is usually a procedure that refers to larger trees.


Bracing is the support of the tree’s branches or limb structure by mechanical means in order to extend its safe, useful life expectancy. Cable bracing involves the use of bolts drilled through the trunk and connected by steel cables. Cobra bracing is the use of nylon rope encircling the trunk and connected to itself. Similarly tree branches/limbs can be supported with steel props installed in the ground.