Hedges come in many shapes and sizes, and different plants. Typically a hedge needs to be trimmed annually. Reduction in height is often needed, requiring a particular skill to achieve a level finish. Check with neighbours before going ahead with the work if your hedge is a boundary to your property (they may assume ownership to half the hedge!), perhaps they might wish to share the cost of height reduction. Operating hedge trimmers and long reach trimmers and/or chain saws requires a particular skill and in certain cases a licence, and is subject to H&S regulations.