Concerns on Cypress Leyland Tree
Hi There, I have two Leyland trees, one is at the front of the house and another is at the back. Both of them do not look good. Their bottom/inside needles are turning brown/turned brown. I notice similar trees in my neighborhood are having the same problems, however my trees seem to be in worse condition. I did pull out a handful bagworms at the bottom of the front tree. I can not see anymore of them. Can Bagworms cause damage to these trees? Please give your advice and recommendations. Should I prune the dead branches? Thank you for your help.
Many Leyland cypress trees are showing winter damage now. This recent article from our plant pathologist explains this issue and some of the common diseases that cause dieback. https://marylandgrows.umd.edu/2018/04/11/why-is-leyland-cypress-turning-brown-winter-took-its-toll/ Wait a while to see if new growth develops in the spring. If the cold weather did not injure the branches, new growth will emerge and brown needles will drop off naturally. Any severely damaged branches should be pruned above where green color is still visible. Do not cut into wood with no foliage. It will not regrow.
Bagworms can also be a problem in Leyland cypresses. Methods for controlling bagworms are included on the following page of our website: https://extension.umd.edu/hgic/bagworms-trees-and-shrubs