leyland cypress dyng

Asked May 19, 2015, 8:47 AM EDT

Our Leyland Cypress trees are about 16 years old with many of them being over 25ft high. When we planted them they were 4 to 5 ft apart and encircled our property in Ellicott City , Maryland Several years ago I notices some in the front yard had some brown branches where I thought dear may have eaten them. Now the brown seems to be moving up the tree and over to others. Please suggest an action to prevent this from spreading. Is there anyone locally to come out an see and treat or give plan for me to follow. Our home is 30 minutes from College Park and I would value the help ? Thank you,

Howard County Maryland

3 Responses

Many leyland cypress have been impacted by our cold winter and are displaying winter damage in varying degrees. An unusually cold winter can take their toll on these minimally hardy trees. All you can do is prune out dead plant material. Scratch the branches with your fingernail and look for green tissue. If you see it, the branch is still viable. Some light pruning may stimulate new growth. Keep the trees watered in dry periods and make sure mulch is not thicker than several inches and keep away from the base of the trunks.
There are also several insects and diseases that can impact Leyland cypress, not to mention problems caused by improper planting, root damage and other abiotic problems.
You can send us digital photos for more information. Send photos of the whole tree, around the base, and affected branches.
For an onsite diagnosis regarding the health of the trees contact a certified arborist http://www.treesaregood.org/

Thank you for your information. Upon following thru with more research I think the damages maybe due to the very cold winter weakening them and they could be being attacked by Cercospora Needle Blight. I think this i the problem because they do not have any visible Cankers or scares. They are just drying up,getting brown and dying. I spoke to a tree farm person who said they too have had a lot of damage. They are pruning the dead area and fertilizing with Milorganite.
Another place said to use Liquid Copper Fungicide on each tree, every two weeks.
What course of action would you suggest??

We are hearing of very large amounts of winter damage on evergreens from last winter. This is primarily a dessication, or problem related to drying out branches. Dead areas can be pruned out.
We would need to see some photos of your tree to help you further, but either way, no, we do not recommend fungicides being sprayed on large trees by homeowners.
If you want to prune and fertilize, that would be o.k.
Given the number, size and importance of these trees to you, it is advisable to have an on-site consultation with a certified (ISA- International Society of Aboriculture) arborist, who specialize in tree health and treatment alternative. Should your trees need any treatments, they would have the expertise and equipment to do the job.