Fast-growing Leyland cypress trees attain a height of up to 100 feet at maturity. Pruning helps to control and shape the growth. You need gardening gloves, pruning shears, a drop cloth and bleach.
Prepare the equipment
Lay a drop cloth under the tree to catch the cuttings. Disinfect the shears in 1 part water and 9 parts bleach.
Shape the tree
To ensure the tree has only one main leader, prune off other main stems when the tree is planted. In early spring, after a year of growth, trim all branches back to the same length. Check that no more than three or four side shoots are growing in the center. After 2 years of growth, cut off all side shoots to encourage branch growth around the leader. After 3 years of growth, once again remove extraneous side shoots.
Prune and trim the tree
Do major pruning and trimming of a Leyland cypress in early spring before it begins its yearly growth. Cut off any damaged or diseased branches flush with the trunk. Light pruning and trimming to control height and shape can be done from spring to mid-summer. Avoid fall pruning, as the new growth it stimulates may be damaged by low temperatures.