Late fall to early winter is the time to protect narrow upright arborvitae such as ‘Emerald Green’ (also called ‘Smaragd’) and ‘Degroot’s Spire’ from winter damage. Young, multi-stemmed plants are especially prone to being splayed apart by heavy snow or ice.
In most cases, you can simply twine jute string around the evergreen by starting at the base and working your way to the top. Tie the string so that it is firm, but not so tight that the branches are damaged.
If deer are an issue (they typically adore arborvitae), you can gently wrap the shrubs in burlap, or better yet, insert four wooden stakes around the plant or hedge (within six inches of the branch tips) and circle the stakes with burlap, stapling the fabric to the posts as you go. Make sure the burlap wall is at least 8’ high for taller arborvitaes, to account for snow accumulation that can become a natural stepping stool.
By taking these precautions, your evergreens will have a better chance of making it through the winter and thriving come spring.