Plant red maples in spring or fall for best results. Water your potted red maple prior to planting to ensure the root ball is thoroughly saturated. This helps minimize transplant shock. Dig a hole that is two times wider than the root ball. Place your tree level in the hole. Buy Acer Rubrum Trees Online The top of the root ball should be slightly higher than the existing soil line. This helps you to avoid planting too deep. Next, fill the soil back into the hole around the root ball.