You can grow apple trees from seeds, but you shouldn't try this if you want an apple tree that will end up producing fruit. The chances that an apple seed will grow up to a fruit-producing tree are very slim, because the seed is usually borne from a hybrid apple. Germinating the apple seeds is also hit-or-miss. Your best bet is to plant plenty of the seeds to increase your chances of getting a few of them to germinate.
Core the apple and remove the seeds. Place the apple seeds into a fine-mesh strainer and rinse them well to remove any sugars or fruit residues.
Spread the seeds on a paper towel and allow them to air dry.
Fill a small plastic bag, such as a sandwich bag, with damp peat moss. Place the apple seeds into the bag with the peat.
Place the bag into the refrigerator for a minimum of 6 weeks. After the 6 weeks are up, remove the bag from the refrigerator and sow the seeds.
Fill a seed tray or 4-inch planter pot with all-purpose potting mix. Plant the seeds about ½-inch deep, spaced ½- to 1-inch apart.
Place the seed tray or pot in a sunny window. Water the seeds three or four times each week to keep the potting mix moist at all times.