Cone-tainers - Tree Seedling Containers Start at $15 for pack of 98 The tall, cone-shaped design and internal vertical anti-spiral ribs let roots grow deep and straight. Each individual cell has a center drainage hole on the bottom and four side-drain holes on the tapered end. SC7 cells have a cell diameter of 1.5" and a depth of 5.5". SC10 cells have a cell diameter of 1.5" and a depth of 8.25". The Cone-tainer tray is 24"L x 12"W x 6.75"H and can hold up to 98 of the SC7 and SC10 cells.