Ailing Leyland Cypress

Asked June 4, 2014, 8:55 PM EDT

I live in northern Adams County, Pa. I have several 12-16ft tall Leyland Cypress bushes that awakened this spring with large areas of brown foliage. Some of the branch tips snap off when bent. Can these grand ole bushes be saved? Would trimming the brown foliage help or must one cut off the entire branch where the foliage is mostly brown or all brown? Can anything be done to restore these beautiful bushes to their glory? I suspect the extremely cold temperatures coupled with the last snow in early spring caused the damage. Thanks in advance for any guidance. Jeff

Adams County Pennsylvania

1 Response

Your assumption is likely correct. Leyland Cypress suffered damage like so many other trees and shrubs from this past winter’s severe weather. High winds, strong sunlight in below-freezing temperatures, snow and ice can prevent the Leyland cypress from being able to maintain an ample flow of water during the winter months and can lead to damage or even death of the tree.

Winter damage is evident when the needles of evergreens such as the Leyland cypress turn brown from the tips. It is called leaf or needle desiccation. This occurs when plants lose water through transpiration faster than roots can draw in moisture from the soil. It is prevalent in the winter because that is when the soil freezes, making water unavailable to the roots. In spite of cold temperatures, bright sunshine can actually heat the leaves internally, causing transpiration or water loss.

In addition to the browning of needles at the tips, Leyland cypress trees may display other symptoms if the case is more severe. The browning or drying out can move inward and affect branches and twigs as well. Needles and branches take on a burned look, and needles can begin to drop. In severe cases, the drying out can kill the tree. In some cases the browning is a result of cracked or split branches caused by the weight of ice or snow or from severe winds. These damaged branches cannot supply water efficiently to the tips beyond the split. Symptoms may be worse for trees with strong sun or wind exposure, particularly on the side of the tree that receives the brunt of the sun or wind.

There is no actual treatment for winter damage on Leyland cypress tree. Before any steps are taken, the damaged tree should be allowed to begin spring growth. If the damage did not injure leaf nodes, new growth will emerge, and the browned needles will drop off naturally. If new growth does not emerge, the branch was severely damaged and should be pruned away about one-fourth of an inch above where green color is still visible. Leyland cypress trees are tolerant of heavy pruning, but if more than one-third of the tree is damaged, the tree may need to be replaced.

In summary, your Leyland cypress may survive. Judicious pruning may reduce the visible effects of the browning.