Emerald Arborvitae

How far is 5-foot high arborvitae emerald being planted to form a hedge?

I placed a wall between them 3 'on center. It was a bit more than most places of the recommendations, but he made a barrier of protection for personal information Nice. That is 2 1 / 2 years. they are becoming bigger (6 ', or more now) and they are barely touching the sides. They are likely to crowd each other a bit, but I really wanted a solid wall. For now, they have no spots or browning thin from lack of sunlight (Michigan climates). I walls with burlap in winter, and they remain green throughout the year.