I wonder if anyone here can tell me which variety of ilex crenata is shown in the two attached photos? Also, I want to plant seven of these crenata in a cedar planter box measuring 61 inches long x 18 inches wide x 26.5 inches high. The planter box was built by me and has drainage holes in the bottom. Can anyone suggest what components to fill the box with, e.g. type of soil, plant food, mulch? I will be using either 3/4 gravel or lava rocks to facilitate drainage. Any advice?