We just planted about 30 emerald cedars (5-6 feet tall). We planted them in Sept. They get plenty of water and sunshine but we noticed most of them are browning on the INSIDE with a few brown branches sticking out but mainly it’s the middle trunk area and we need to separate the branches to see it. In doing research we came across the term ‘fall needle drop’ but not sure if this is how it looks. It’s affecting almost all of the trees in various degrees and we’re worried. The outside leaves/ quills are quite green and generally look healthy.
Emerald Cedars generally drop some needles in the fall and/or spring from the “inside” of the trees, so this is a perfectly normal occurrence. In your case, the trees are newly planted so they may be shedding more needles at the moment due to the stress/shock of being moved into their new location. I would suggest you keep watering them well until freeze up, and early in the spring begin watering again as soon as you can get your hose or irrigation system hooked up. Mulching around the base of each tree will help keep weeds at bay and also help retain soil moisture but make sure the mulch is kept away from the tree trunk.
If the needle browning and drop was on the “outside” of the trees, I would be concerned about spider mites, aphids, fungal diseases, animal urine (dog) or severe lack of moisture/drought.
I’m sure your trees will be fine if you keep them well watered. Hope this helps.