drought damaged plants
One plant I think is a Leland which is very brown now (Jan 3, 2020) and the other plant I think is an ilex crenata. My question is, are they so damaged they will die? Is there something I can do with the ilex crenata like cuting it back just before the springtime? Thank you,
There may be several reasons for dieback on the ilex crenata such as root rot and/or voles. The browning of the foliage and branch dieback is most likely due to a root rot. Japanese hollies are very susceptible to black root rot and can be an issue in heavy soils with poor drainage. We had excessive rain the last several seasons and drought last summer which affected the roots of many woody plants.
Also, check around the base of the plants for holes about the size of a silver dollar. If you see this, suspect voles. They feed on the roots of trees and shrubs and cause dieback https://extension.umd.edu/hgic/topics/voles
All you can do is improve the drainage in the area and look for vole damage.
The plant is not worth saving as the dieback is going all the way to the top of the plant.
Leyland cypress - the plant is also not worth saving and will not return to its former glory. 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, poor drainage, etc.)
can lead to disease and insect (bagworms) issues.
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