Leyland cypress trees are fast-growing evergreen trees that thrive in a wide range of imperfect soil conditions. They reach up to 50 feet in height and up to 25 feet in spread at peak growth. They have an upright pyramid growth habit and are commonly planted en masse for use as hedging, screening, windbreaks, property-line demarcation and to frame distant vistas. Leyland cypress trees require only light fertilizer applications and annual topdressing to maintain healthy growth and green color.
Fertilize your Leyland cypress tree twice each year in the spring and again in the early fall. Use a slow-release granular fertilizer with a high-nitrogen formulation containing phosphorous and potassium and micronutrients, if available. Choose a product with a guaranteed analysis near 22-4-8. Follow the recommended dosing on the label for your acreage and age of cypress trees.
Spread the granules starting a few inches out from the trunk to a few inches past the outer drip line of the tree all the way around the tree. Scratch the fertilizer granules into the top inch or two of soil with a cultivating fork or spade to work them into the soil.
Water the cypress well until drenched to settle the fertilizer into the soil and begin the release of nutrients. Water frequently enough to keep the soil uniformly moist but not wet at all times.
Mulch around your Leyland cypress with a 3- to 4-inch-thick layer of well-aged manure or compost each year. Apply the mulch staring 6 inches out from the trunk to at least 6 inches past the outer drip line of the tree. This will boost the soil quality, hold moisture in and keep competitive weeds from cropping up.