A hedge looks right only if the shape is cut while the plant still has time to recover. A cut that is too late and too hard leaves the hedge thin until the next summer.
When should a hedge be cut?
In late summer, when the strong growth is over but before the nights are properly cold. Then the hedge stays tidy into winter and does not shoot straight back. A cut too early, in the middle of growth, means the same job is done again in September. A cut too late, after growth has stopped, leaves the cut surface open to frost. August is usually the window, not October.
Can I cut it myself?
A low hedge, yes, if you keep both sides even and do not cut back into old wood. Keep the hedge a little wider at the bottom than at the top, so the base gets light and does not thin out. A tall hedge and a ladder are a different job. Wet ground, a power line and the neighbour's boundary make it dangerous quickly. If you cannot reach both sides from the ground, do not stretch.
What usually goes wrong?
The hedge is cut too narrow in one go, or only the street side. Next summer the other side is full of gaps, because light never reaches the base. Another mistake is leaving the cuttings at the foot of the hedge. They smother the base and look unfinished all winter. A third is cutting every shrub to the same measure, even when some are conifers and some are deciduous. They do not take the same cut.
What about large trees behind the hedge?
A branch that reaches the roof, a path, or the neighbour is not a hedge-shear job. It needs someone who can work up high safely and knows where the branch may fall. Do not saw a branch from a ladder if it is thicker than your wrist, or if there is a roof below. Ask before the saw is in your hands. A bad cut on a tree does not close the way a hedge does.
When should the work be handed on?
When the hedge runs for tens of metres, it is tall, or the cut has been skipped for years. Then the hedge is bare inside, and one hard cut makes it worse. Trees, shrubs and leaves brings the line back without leaving the hedge bare in a single visit. The work can be split over two summers if the hedge has grown badly past its line.
What waits until later in autumn?
Raking leaves and clearing gutters. In August you set the shape. The leaves come afterwards, and cutting should not be mixed with them. If cuttings and leaves go in the same heap, neither comes away cleanly. Shape now. Leaves when they are on the ground.