I plan to use a hedge of Arborvitae, Danica 1' - 2'H 2' -3'W Globe Shape behind a double stacked row of rocks. I will have room for planting perennials behind the hedge row. (6'6" along deck to point of Large Green Septic Tank Cover x 9'6" along house). Have included photo of site. What suggestions can I get for plantings? I originally wanted Ferns & Hosta but don't want everything to go "dead" during the winter. I do want to have a large black pot 26" wide x 18" high incorporated in front of the hedge to use shade plants in it. This area faces east and Lake Huron is about 100 ft. in front of this spot.