How to Maintain Hedges: HOW TO STOP A LEYLANDII HEDGE GROWING TOO TALL

The simple answer is to keep it trimmed to the desired height! Get out the manual or powered clippers a couple of times a year and your Leylandii hedge will be easily managed and maintained.
• Don’t cut back too hard or too far – its dead wood will not regenerate.
• Remember NOT to cut or even trim after August, as this can encourage bare patches.