Arrange the plants in the landscape before you begin digging holes, to ensure you have enough cypress to cover the area. Place the first cypress where you want the hedge to begin, then place the second one 15 feet away and 15 feet behind the first. Place the third cypress 15 feet away and 15 feet in front of the second.
Continue placing the young Leyland cypress in the same fashion, staggering each cypress 15 feet apart and alternating one tree forward and one tree back. This double-row staggering will provide a wall of green once the trees fill in.
Dig holes in the spots where you have placed the trees. Make the holes twice the width of the containers of the trees. Do this at least six weeks before the first frost of winter.
Remove the first tree from the container. Loosen the root ball with your hands and spread the roots, then lower it into the planting hole. Backfill the hole with soil, firming it with your hands as you go. Continue until the cypress is planted at the same depth it was in the container.
Repeat the planting process with each tree. Water until the soil around each tree settles.