specialty pruning technique in which a tree with a large-maturing form is kept relatively short. Starting on a young tree. internodal cuts are made at a chosen height. resulting in sprouts. Requires regular (usually annual) removal of the sprouts arising from the same cuts. Callus knobs develop at the cut height from repeated pruning.
Pollarding, a pruning system involving the removal of the upper branches of a tree, promotes a dense head of foliage and branches. In ancient Rome, Propertius mentioned pollarding during the 1st century BCE. The practice occurred commonly in Europe since medieval times, and takes place today in urban areas worldwide, primarily to maintain trees at a determined height.
Traditionally, people pollarded trees for one of two reasons: for fodder to feed livestock or for wood. Fodder pollards produced "pollard hay" for livestock feed; they were pruned at intervals of two to six years so their leafy material would be most abundant. Wood pollards were pruned at longer intervals of eight to fifteen years, a pruning cycle tending to produce upright poles favored for fence rails and posts and boat construction. Supple young willow or hazel branches may be harvested as material for weaving baskets, fences, and garden constructions such as bowers. Nowadays, the practice is sometimes used for ornamental trees, such as crepe myrtles in southern states of the USA, although the resulting tree has a stunted form rather than a natural-looking crown.
Pollarding tends to make trees live longer by maintaining them in a partially juvenile state and by reducing the weight and windage of the top part of the tree. Older pollards often become hollow, so can be difficult to age accurately. Pollards tend to grow slowly, with denser growth-rings in the years immediately after cutting.