Leyland cypress (x Cupressocyparis leylandii) is a fast-growing evergreen tree that is often used as a privacy screen or hedge. While it is a tough tree that can tolerate a wide range of conditions, there are a few issues that can occur. Keep an eye out for the following problems when growing Leyland cypress.
1. Canker Disease
One of the most common problems with Leyland cypress is canker disease. This disease is caused by several different fungi, including Phomopsis juniperovora and Seiridium cardinale.
Canker disease causes sunken, dark brown lesions to form on the branches and trunk. The bark may crack and ooze sap. The affected branches will eventually die back. To prevent canker disease, choose a planting site with well-drained soil and avoid overhead watering. If possible, purchase disease-resistant cultivars such as ‘Castlewellan' or ‘Naylor's Blue'.
2. Spider Mites
Spider mites are tiny pests that feed on the foliage of Leyland cypress trees. They cause the needles to turn yellow or brown and can eventually kill the tree if left unchecked.
To control spider mites, hose down the tree with water every few days or use an insecticidal soap or oil spray. You can also release beneficial predators such as ladybugs into the garden to help keep the population in check.
3. Root Rot
Root rot is another common problem with Leyland cypress trees. It is caused by several different fungi, including Phytophthora cinnamomi and Pythium ultimum.
Root rot affects the roots of the tree, causing them to turn brown and mushy. The tree may become stunted or die outright if the roots are heavily affected. To prevent root rot, choose a planting site with well-drained soil and avoid overwatering. If possible, purchase root rot-resistant cultivars such as ‘Nootka false cypress or ‘Humei'.
4. Needle Blight
Needle blight is another fungal disease that can affect Leyland cypress trees. It is caused by several different fungi, including Phomopsis juniperovora and Seiridium cardinale. Needle blight causes brown spots to appear on the needles, which eventually turn yellow or brown and drop off prematurely.
The affected branches will eventually die back. To prevent needle blight, choose a planting site with well-drained soil and avoid overhead watering. If possible, purchase disease-resistant cultivars such as ‘Castlewellan' or ‘Naylor's blue'.
5. Winterburn
Winterburn is a condition that occurs when the leaves of Leyland cypress trees are damaged by cold temperatures during the winter months. The leaves turn brown or black and may drop off prematurely. Winterburn is more likely to occur in areas where the winters are harsh and dry.
To prevent Winterburn, choose a planting site that offers some protection from cold winds and make sure to water regularly during dry periods in winter. You can also apply a layer of mulch around the base of the tree to help insulate the roots against cold temperatures.”
Conclusion:
Leyland cypress (x Cupressocyparis leylandii) is a fast-growing evergreen tree that is often used as a privacy screen or hedge in gardens across North America; however, there are a few problems that commonly occur with this species! Watch out for canker disease, spider mites, root rot, needle blight, and Winterburn when growing Leyland cypress in your garden!
