Question
I live in in Ma near the RI line.  I want to plant 60 to 90 of these trees to form a privacy fence in my back yard.  About 140' wii be along a marshy forest of swamp maples.  If I dig down 6" to 10" It will be very wet, will it be too wet to plant the green Thuja's?  How deep will I have to go to plant the 1' to 2' trees I plan to buy? I deeply appreciate your help, thank you

Answer
Arborvitae WILL GROW IN ADVERSE SOIL CONDITIONS like heavy soil, that's clay (argillaceous soil), wet soil (that's saturated soil), rocky soil , sandy soil (arenaceous soil) and somewhat acidic soil or basic (alkali) soil.
The depth of planting will be determined by the rootball of the tree. Plant only as deep as the bottom of the rootball to the top of the ground on the rootball. Make sure the new hole is twice the width of the root ball and fill with good top soil.  This will give the roots an area to spread laterally. The problem may come in the fact that the root systems will not be very deep since they can get water at a shallow depth this may lead to wind throw later as they get larger. As long as there is not standing water I think they will do great. The problem will be more in getting them planted in the wet soil than the wet soil harming the trees.