Remove the apple seeds from an apple core. Place them on a paper towel to dry in a cool place. The refrigerator is a good place. Leave them there until there is no moisture on the outside of the seed.
Place the apple seeds into the potting mix about a half an inch deep. Place the soil in a sunny area and be sure to maintain the moisture levels. Ideally, you want the temperature of the soil to remain between seventy and eighty-five degrees.
Continue to monitor the soil and sunlight of the seedlings as they begin to sprout in a week or two. Water the potting soil when it gets dry but be careful not to over-water the seedlings. Be sure that they each have enough room in their containers. When they become too big for their current containers, repot them into bigger containers.
Transplant your seedlings to the ground outside when they reach about two feet tall. Choose an area that gets plenty of sunlight. Remember that this is the last time you will be replanting your apple trees, so choose an area where they will have plenty of room to grow. Dig the hole much wider than the roots because this softens the ground and allows the apple trees to root much more easily.