A few months ago I purchased and planted 15 emerald green arborvitae. They all look to be doing well except for one. It has basically turned completely brown and I don't think there's any hope for it. My question is, how can I prevent this from happening to the others? I planted, fertilized and mulched all of them the same. I've continued to water them throughout the summer. The one that is brown did look the worst out of the bunch when I planted them but it still wasn't "dead" like it looks now. Just looked a little malnourished. I used Miracle Gro plant and shrub spikes and placed about 4 inches deep of mulch around them going back 2 feet and in front 2 feet. Thanks, Annetra