Leland Cyprus - lower branch foliage loss
Two mature (14-yr old) Leland Cyprus trees I planted in my backyard have been losing foliage on their bottom tier branches over the past three years. The trees are near a bird feeder and have endured a lot of bird perching and droppings, but I can think of no other stressor that might have caused this die back. There has been some hill erosion of the soil near the base of the trees but no root exposure that I can see. I have hosed the branches down periodically to try washing off any mites or other predatory insects but I’m not certain it is having any effect. I’ve uploaded a few shots of the affected limbs.
Montgomery County Maryland
We are hearing of many problems and declines of leyland cypress, which begin to show up at the 15-20 year mark. They are not really well suited to our climate long term. Stresses such as winter injury, too much shade, planting too deeply, etc.
can lead to disease and insect (bagworms) issues. Your tree looks like it is located in too much shade and there may be root competition for moisture and nutrients.
Here is more information, from our Maryland Grows blog recently written by our plant pathologist:
and the diseases most prevalent: https://extension.umd.edu/hgic/topics/seiridium-and-botryosphaeria-canker-leylands-trees
All you can do is prune out dead branches. Keep watered during dry periods and make sure mulch is no thicker than several inches and keep away from the base of the trunk. The tree will most likely limp along but will not return to its former glory.