Leyland Cypress trees going brown

Asked June 26, 2016, 7:37 PM EDT

I have a row of Leyland Cypress trees at the edge of my property. They are about 20 years old. This month, I've noticed some of them have begun to go brown. Are they at the end of their natural life span, or might there be something infecting them that I could treat? Thank you for your help.

Frederick County Maryland

3 Responses

There are several insects and diseases that can impact Leyland cypress, not to mention problems caused by improper planting, root damage, cold damage, and other abiotic problems. Leyland cypress do not recover well from any type of root loss. They grow best in full sun with plenty of air circulation and appreciate moisture during dry periods.
You can send us photos of the whole tree, around the base of the tree, and affected foliage so we can see what you may be dealing with.

Thank you for your prompt response. I have attached some pictures, and thank you for your help.

We think this is probably a combination of factors at work, primarily environmental/weather.
That said, you are not alone. Our plant pathologist is getting reports from all over Maryland of stressed and browning Leylands.
Part of the problem is that these were the favored plants to use for screening about 20 years ago and we are finding that for our climate that is about when problems begin to appear, including the natural shedding of needles where they become shaded, among other things.
If you decide to replace Green Giant Arborvitae or a mix of other evergreens and shrubs including holly would be a good idea.