The Leyland cypress tree (x Cupressocyparis leylandii) is an evergreen that can easily attain a height of 75 feet with a 20-foot spread. The tree is known for its astonishing growth rate. It can easily attain 3 feet or more of growth per year. Leyland cypress are popular trees for a hedge or windbreak. In a few areas of the United States, the tree is commercially grown as a Christmas tree.
The Leyland cypress can thrive in full sun or partial shade. The tree requires well-draining soil conditions with abundant organic matter. Standing water around the root system of the tree can kill it. The tree can easily withstand a drought once established. It is also highly resistant to salt, which makes it ideal for planting along a coastline. The tree is easy to grow and offers a 95 percent seedling survival rate, according to the University of Georgia Center for Invasive Species and Ecosystem Health.
Pruning and Shearing
The Leyland cypress will benefit from regular pruning in the spring and fall. Pruning away dead or diseased wood can help the tree survive hard winters with heavy snowfall. The tree should also be pruned to increase air circulation by removing branches next to the trunk. Leyland cypress trees can be tip-sheared along each side to give a more uniform appearance and for hedge growth. Shearing can safely take place each spring and fall.
Leyland cypress trees should be planted a minimum of 8 feet apart when grown as a hedge or beside other trees. The tree branches are delicate and rubbing can cause wounds on the tree. For best planting success, only established seedlings or older trees should be planted. Soil with a pH of 5.5 to 6.5 is ideal. Leyland cypress seedlings and young trees should be kept moist but not water-logged during the first few years. Each spring the Leyland cypress will benefit from a balanced fertilizer application such as 6-6-6.
The Leyland cypress is a sterile tree incapable of producing viable seeds. The tree can only be propagated through cuttings. A tree that is over 10 years old will stand between 30 to 40 feet and should be avoided for propagation cuttings. Cuttings should be from new growth that is upright with relatively hard stems and green foliage. A 6- to 8-inch cutting is ideal to place in a potting medium and root.
Pests and Disease
Bagworms and spider mites feed on the tree but can easily be washed away using water. The tree is prone to Phytophthora root rot and numerous canker diseases, however. The canker diseases have no cure. Applying the fungicides Zertol and Daconil can help slow the spread of the diseases. Drought tends to make the diseases worse. Phytophthora root rot can be prevented by not allowing the trees roots to become water-logged. If the tree is afflicted with the fungus, an application of the fungicide Zertol is effective.