Article: Apple trees must be planted in pairs in order to bear fruit—apple trees are not self-pollinating, so they need a different kind of apple tree to pollinate with. You can either extract the seeds from an apple you are eating, or buy apple seeds at the store. Keep in mind that growing an apple tree from the seeds you have collected does not necessarily guarantee that the tree produced from these seeds will bear fruit or be the same kind of apple. Try to pick or buy seeds of apple trees that do well in your climate zone or else your tree may die once planted outside.  If you want to grow apples for their fruit, it is recommended that you buy a sapling tree from a nursery rather than growing an apple tree from seed. To learn how to transplant a young tree, click  here.  When attempting to grow an apple tree from seed, you should also keep in mind that the tree produced will not have any dwarfing characteristics (meaning that it will grow to its full height of about 30 feet/9 meters). If you think you have enough room in your yard for this tree, great! You should also keep in mind that trees planted from seeds could take 8 to 10 years to produce fruit, while a transplanted sapling will produce fruit in a much faster time frame.

What is a summary?
Collect two different kinds of seeds.