Here are a few tips to help evergreens, such as arborvitae, survive the first winter:
Make sure the ground around the arborvitae is staying moist and give them a good amount of water before the ground freezes. A good rule of thumb is one inch of water, either through rain or by watering until ground freeze. A slow trickle is best so the water soaks into the soil, reaching the roots vs. running off.
Spray the arborvitae with Wilt Stop 2 times before the freezing weather arrives. Spray the first time around Halloween and the second time before Thanksgiving. The weather must be warm enough that the spray will dry on the plant and not freeze. Spray until the point that the leaves begin to drip.
If we get some warm weather mid-winter; dump a couple buckets of water around the trees.
Most of the winter burn on arborvitae is due to the tree drying out and NOT from the cold temperatures.