Leyland cypress is a large evergreen tree growing 60 to 70 feet tall and 12 to 20 feet wide. Its conical shape and dense dark green foliage make it perfect for a hedge screen. Unfortunately, this attractive tree is susceptible to diseases. In order to keep it healthy, you must know how to care for it properly. Part of the care regimen is fertilization and pruning. Knowledge of when and how to prune and fertilize a Leyland cypress tree will help you keep this tree healthy.
Fertilize the Leyland cypress in early spring with a slow-release fertilizer. Look for a time release of eight to nine months. This will release nutrients to the cypress throughout the year.
Mix 1 inch of well-rotted manure into the the soil around the cypress, also in early spring. The combination of the manure and fertilizer will provide optimum nutrients to the plant.
Prune the Leyland cypress in winter when it reaches 3 to 4 feet tall. Clip up to 3 to 4 inches of growth, only from the sides of the tree. This will encourage the tree to grow thicker.
Prune out diseased branches as soon as you notice symptoms such as yellowing foliage. Cut to healthy wood and throw away all infected tree materials.