Landscape - Dead Leyland Cypress

The drought affected our Leyland Cypress trees last year with many showing sypmptoms ranging from branch dieback to whole tree death. The following is information on this problem.

There are many dead leyland cypress trees in the landscape, especially downstate. Most of the deaths appear to be drought related, but we are also seeing a combination of drought and a fungus disease called Seiridium canker. Seiridium canker is favored by drought stress and causes branch infections that lead to scattered dead branches. If undetected and not pruned the fungus can move into the trunks and cause tree death particularly in small trees. Evergreens should be planted in the spring or in the early fall to give them time to get established before cold weather sets in. Deaths of recently planted trees may be due to late fall planting and the fluctuations in temperature this winter.