How Much Can I Prune Off My Leyland Cypress?

Q: I have twenty Leyland cypress trees in full sun. I wish to make it look good and lower the overall height. What is the maximum amount I can prune from the top and not risk detrimental consequences? 

A: Leyland cypress can be maintained as a nice hedge. The trick is to go in and make deep cuts twice a year, in early April and early August. Reduce a thick, coarse branch by pruning back to a smaller, finer branch. In this way, a soft, fine-textured look can be achieved and maintained. Never reduce a Leyland’s height by more than a third. Once topped, it must be maintained; otherwise, multiple leaders develop, producing a weak top that’s prone to failure. If you need to remove three or more feet of height, do it in late February. Always prune back to a branch; never leave a stub. Understand that this becomes a regular commitment of your time to properly care for the plant.