Think carefully before planting a Leyland cypress. Many people plant Leyland cypress as a hedge, not realizing that it can grow to more than 100 feet tall and can require a great deal of time and energy to keep it looking like a hedge. The trick to keeping a Leyland cypress trimmed is to make frequent small trims rather than one large one.
Make frequent small cuts to the ends of the branches of your Leyland cypress to modify both its shape and its height. Hand-operated pruning shears work best -- power hedge trimmers frequently cut too much at a time.
Cut back to green wood and no further. Cutting back to brown wood could result in a permanently brown or dead spot in your hedge or tree.
Cut the top of your Leyland cypress frequently if you plan to grow it as a hedge. Frequent topping is the only way to keep your hedge's height under control. During the warm growing months, trim as often as once per week.