By way of background, we planted 8 Emerald Green Arborvitaes in June of last summer. We live in Middle Tennessee (zone 7). Unfortunately, we planted them in the middle of a very hot drought which lasted a few months. We watered regularly but were sure not to over water. The trees thrived for three months and grew a good 1-2 feet until September/October when they suddenly started to brown and get considerably thinner. I fertilized them this past March, cut away any dead/browning areas and removed the natural inner brown needle fall from winter to encourage circulation. Now, they seem to be producing some new green on top, a little on the bottom but not bulking out or filling in too much in the middle and they are still very anemic looking.The tips of some of the new growth have turned brown a bit in a few areas. Trying to figure out what is going on. Soil is very good and not too moist. I see no evidence of bag worms. Could it be a fungus? Should I treat the trees with anything in particular? Grasping at straws here! Thanks so much for any advice you may have!

This looks like weather related damage/stress to me. The key is these are very newly planted arborvitae and they are still establishing their roots. Very new growth at the tips can be browned by too much sun, too much wind, early frost, etc. As long as you are seeing new fresh growth on the trees and no moldy areas or the dreaded bag worms, I would think time is all that's needed. I've got two massive hedges of arborvitae; they can look a little scrappy until they get really well established. To get the middle portion to fill in, you could try pruning back the top. It will stimulate outward pointing growth that will bulk up the plants.

Check out this webpage from an extension service:
https://ask.extension.org/ques...

LysmachiaMoon said:This looks like weather related damage/stress to me. The key is these are very newly planted arborvitae and they are still establishing their roots. Very new growth at the tips can be browned by too much sun, too much wind, early frost, etc. As long as you are seeing new fresh growth on the trees and no moldy areas or the dreaded bag worms, I would think time is all that's needed. I've got two massive hedges of arborvitae; they can look a little scrappy until they get really well established. To get the middle portion to fill in, you could try pruning back the top. It will stimulate outward pointing growth that will bulk up the plants.

Thank you! Yes, I was thinking the same thing. They are still young and only a year old. They are hanging in there but just wanted to rule out any disease. I was concerned that they are being affected by leafminer but I can't find any little caterpillars on the leaves anywhere. Will head over to your link now.

Hugs,
Jane