May, Jun, Jul, Aug, Sep
Use long bamboo canes to mark the top edge along one side of the hedge. Push the canes down into the hedge.
Tie strong string between the canes to mark a straight edge as a guide to cut to. Check the string line is taut.
Trim the top of the hedge by holding the hedge-trimmer horizontally with both hands and using the string line as a guide. Wear protective goggles and gloves and make sure you have a firm footing on a ladder or a platform for tall hedges.
Clip the sides of the hedge using the string as a guide. Hold the hedge-trimmer vertically and make long sweeping strokes to ensure an even finish.
Remove the canes and string line before using the hedge-trimmer to tidy up the top edges. Hold the cutting bar at a 45-degree angle.