These are fruit trees - such as apples, pears and cherries - which are carefully pruned into various shapes, to keep them small and to encourage the highest yield for the space they occupy. Examples of shapes used are: cordon, fan, and espalier. These forms require initial training along supports. If kept below 1.8m (6ft) in height, they are easier to pick than conventional, unrestricted trees. Open, unsupported trees can also be restricted slightly, into pyramidal, or spindlebush forms. Restricted friuts are generally pruned more in summer than winter.