When does a tree have to be pruned?

Pruning - trees have to be pruned to protect their health, improve their appearance or remove danger to people or property. Sometimes it is necessary to remove broken, dead or diseased branches, to restore vigour to an ageing tree by cutting back and to admit more air and light by thinning out the centre. One of the most obvious reasons for pruning trees to control their growth within the space available for them to flourish. In this type of pruning, live pruning as it is called, branches are lopped from the trees to control their size and to maintain a pleasing shape. Sometimes trees are "topped" by removing some of the upper trunk. Pollard pruning involves cutting the trees back to a point at which strong branches are to be allowed to grow. As shoots grow from these points they are cut back each year. This method makes a very ugly tree shape. The lightest method of pruning is known as drop-crotching, which trims only the upper and outer branches. Another type of pruning is orchard pruning, for stimulating the production of flowers and fruit on fruit trees. Here the farmer tries to maintain a framework of branches which will best allow the sunlight to penetrate to the middle of the tree's crown. Most deciduous trees may be pruned at any time of the year. The pruning of evergreen trees with needle like leaves should normally be limited to the removal of dead wood. Dead pruning, or brashing, is the cutting away of dead or dying side branches, most often used with conifers growing in plantations. The last type of pruning is side shoot pruning or shrouding, which means the removal of small side branches on such trees as pollards or limes to provide a knot free bottom length to timber. Pruning means causing wounds and these may cause disease. Special dressings available at most garden supply stores should be applied to cuts more than an inch in diameter to protect the trees from fungi.