I trim this Leylandii hedge on an ongoing basis for this regular customer in Newton Abbot. Trimming and training it to be straighter and look better is important to its growth and look. It is best to trim your Leylandii hedge in late spring or summer as this gives your hedge a chance to recover and put on a bit or re-growth before the winter. However, watch out for birds’ nests as it is illegal to disturb nesting birds.
Trim your Leylandii hedge once a year, every year. If you trim it more often, the hedge doesn’t get a chance to recover and put on a bit of re-growth before the winter. It also makes it more susceptible to stress conditions such dry or hot weather, cold winters and Cypress Aphid. Recent research indicates that hedges trimmed only once and those trimmed in the late spring or early summer, are unlikely to suffer from any problems. As some of this customer’s hedges grow onto the pavement, trimming has to be done regularly so that the hedge does not restrict the pavement. When overgrown hedges start to impair the pavements or roads the council will write to the owner demanding the work to be done. If it isn’t done, the council will do it themselves and charge the customer 3-4 times as much and not necessarily do a good job.
Some of the earliest Leylandii planted in the UK in the late 1800’s and early 1900’s are still alive and growing, so the answer is “over 100 years” but nobody knows how long they will live for eventually. The National Collection of Leyland Cypresses (Leylandii) is at Bedgebury Pinetum in Kent where several large specimens can be seen.