16 feet or longer.
If your flower bed is 4' square, it will have a perimeter of 16'.
If your flower bed is 48' long and 4" wide, it will have a perimeter of 96' 8".
If your flower bed is 4' square, it will have a perimeter of 16'.
If your flower bed is 48' long and 4" wide, it will have a perimeter of 96' 8".