Apple trees need a good start at planting time to thrive and produce fruit. Site selection, soil amendment and planting require careful attention. Apple tree seedlings from the nursery come planted in pots with the roots in soil. Mail order saplings are shipped bare root wrapped in cloth or plastic to keep them moist. Plant apple trees in the spring when the ground thaws and the cold weather has passed. Purchase 1-year-old apple trees in the spring and plant them as soon as possible.
Choose the site carefully. Apples need at least six hours of full sun each day. Morning sun is ideal because it dries out moisture that collects on the leaves at night. Plant apple trees away from underground sewer or power lines. Apple trees can grow up to 30 feet tall, so choose a planting space away from power lines and buildings.
Amend heavy clay soil with organic matter and coarse sand. Spread a 6-inch layer of one part coarse sand and five parts organic compost onto a 10-foot diameter area and till it into the soil. If the planting site is on low ground, build a 12-inch tall 10-foot diameter raised bed. Fill the raised bed with three parts soil, two parts compost and one part coarse sand. You can plant the tree directly in naturally draining, loamy soil.
Prepare a hole for bare root saplings. Make the hole wide enough and deep enough that all the roots can be spread out in the hole without being bent or twisted. Make a pyramid shaped mound in the center of the hole and drape the roots over the top. The base of the trunk should be level with the surrounding soil. Fill in around the roots and pat down the soil.
Dig a hole for a potted sapling that is slightly larger than the nursery pot. Turn the tree on its side and carefully slide the rootball free, being careful not to break up the soil. Cut plastic pots away from the rootball if you don't mind losing the pot. Unwrap any roots that circle the rootball before placing it into the planting hole. Always plant so that the base of the stem is level with the surrounding soil. Backfill with soil and tamp it down.
Water the sapling until the soil is damp all around the root system. After the first thorough watering, apply 1 gallon of water a week for each new sapling. Apply a 4-inch layer of mulch around the planting site to improve moisture levels in the soil, but keep the mulch from touching the base of the tree to avoid encouraging rot around the trunk.
Apply 1/2 pound of fertilizer to the tree every month for the first season after planting. The University of Minnesota recommends a 12-12-12 fertilizer applied in a circle around the planting site.