Hi. We have several arborvitae in our yard that we planted. I do not know which they are. They are about 20 feet tall and six feet wide. They remain green all year. I discovered a line of seedlings along
the back porch which I am trying to loving nuture to taller trees so I can line our yard for privacy and to be more green overall. I live in Maine where temps drop to minus 20 F the coldest. I have some in plastic pots and I want to place them in my raised beds, add a little extra dirt in between and some hay. Will this keep them alive? Thanks for your help. Anna

If you can, it would be better to sink the pots into the ground for added protection for the roots. Some say there's a two zone difference in temps.