Rodent cages proved necessary on the Dish with large populations of ground squirrels and voles, both of which will eat seedlings and girdle the base of saplings to get at the moist, nutritious cambium layer. These cages extend 18-inches below ground. In this case, you see hardware cloth that was formed into a cylinder and tied with twisted wire along the seam. Later, we found lighter dutty aviary netting sufficient to control rodents. These were also tied at the seams. Despite the fears of of some, our cages are consistently split and sloughed - we have now watched this several hundred times..