Slender and fast-growing at a rate at about 2 to 3 feet per year, Leyland cypress trees are generally grown to meet an urgent need for a mass of evergreen foliage to create a privacy hedge. A needled evergreen, its leaves consist of flattened sprays. Height can vary greatly, depending on the variety and the conditions in which you grow them. For best growth, plant in a full sun site with evenly moist fertilized soil. The average height for an untrimmed Leyland cypress is about 50 feet, but do not be surprised if yours grows much higher or much shorter than that. Taller than they are wide, the spread of this columnar tree is commonly only 1/3 or 1/4 of the height, sometimes less.

Leyland cypress does not tolerate shade well. It grows best in open, sunny conditions and in most soil types, including clay, loam, and sand, acidic, and alkaline. It also tolerates drought and brief waterlogging.

To help its roots get established after spring or summer planting, water your Leyland cypress regularly. A Leyland cypress will take a few months to get established. After that, apply 1 gallon a week to the rootball if you live in USDA zones 7 or 8 and 2 gallons a week if you live in USDA zones 9 or 10. For the first and second years, water your Leyland cypress twice a week through spring and weekly in summer, tapering off to once to twice a month in winter. The older the tree, the longer you can go between waterings. Use soaker hoses, not sprinklers that will wet the foliage.

Leyland cypress trees are best grown in planting zones 6 to 10 with temperature lows of -8 degrees Fahrenheit. However, zone-5 gardeners have been successfully growing them by providing mulch and an A-frame shelter in the winter months to protect them from snow and ice damage. Such sheltering is feasible only while the plants are young—unless you keep them short by pruning. Luckily, once the plants have matured, sheltering becomes unnecessary, as they will prove to be sufficiently cold-hardy in zone 5.

Fertilize Leyland cypress in early spring, before new growth begins. Spread a general-purpose, 10-10-10 fertilizer around the tree's drip line.