Emerald Cedar Issue

(Question)

I have a problem with three emerald cedars planted last year. They looked beautiful until this fall when the upper half of each now have brown growth. Not certain what is happening and if they can be saved. Any help you can provide would be appreciated. See pictures.

(Answer)

Hello – Trying to diagnose plant issues from a photo is challenging.  In your case, I can’t tell if the brown growth you refer to is some kind of plant disease or rather the existing foliage turning brown.  I’m going to assume the latter for a number of reasons.  Firstly, browning of the foliage in cedars is a common problem.  We get many questions from gardeners asking why their cedars are turning brown.

Cedars are known for their love of water. Too much can cause root rot and too little severely stresses the plant.  Both cases can lead to browning.

Also, given that your tree is only a year old, it’s root system will not have been well established.  The lack of rain we experienced in the late summer this year was a stressful time for trees and shrubs particularly those recently planted.

I’m including a link below to our response to an earlier question on browning cedars which provides some good information on watering requirements for eastern white cedar.  (Note that emerald cedar is a common name for the eastern white cedar cultivar Thuga occidentalis ‘Smaragd’.)

Cedars do cast off their third-year needles each year creating some natural browning.  A vigorous brushing with your arm is recommended to shake off the dead foliage. While what you are seeing is more than the annual browning of third-year foliage you could try the same technique now or in the early spring.  You can then assess if your cedars can be saved.  Cedars typically do not put out new growth on old wood so bare spots left by the removal of dead foliage are not going to fill in.

Good luck and if I’ve misdiagnosed the problem, please send us a close up photo of the browning on your cedar.

Eastern Cedars Turning Brown