There is a way for people to start own root apple trees. I live in a clay soil in zone 3 WI. I have taken a bear root grafted apple tree like you buy, and planted it sideways in a trench so i could cover the roots and the truck. The limbs were twisted so they were in the dirt with only the small twigs sticking out the soil about 1 ft. You need some part of the last seasons growth in the soil. Sometimes a rock or some turned over sod is needed in the soil and standing upright. Maybe some kind of mulch like wood chips would keep the weeds down. A shady moist area would help rooting. Next spring check for twigs that have grown a root and cut the twig below the root and plant as soon as the frost in the soil does not stop you. You may need two years if the rooting has not started the first year. Compacting the soil around the twigs might help also. You now have a variety on its own root. That root maybe slow to gain vigor. Winter trimming the top might help. Planting deeper and keeping the top very straight will help. Some varieties have poor root systems that allow the tree to tip. Some will grow very strong roots as that is there character to due so. Now any one can start a new tree from your own root tree from a root off your own root tree. You need a small root pencil size and up to about a foot long. A root from the main trunk and from as high up as you can find one helps. Store that root in a bag with plenty of dirt about 50 degrees for about 4 to 12 weeks or until it starts to grow a shoot. I store the root horizontal and keep the ground almost dry but not damp. I do not allow direct sunshine but indirect light on the root end sticking out of dirt some.Keep the bag sealed with a air space in it. Prevent dehydration and fungus. Plant out when sprouts start growing stems not roots. Plant upright if possible, keep watered and light shade, mulched, prevent weed competition. Any sprouted stems from the own root system can be started after frost is out of the ground, even if the sprout comes off the large roots without roots of its own. Cut the sprout stem as close to the main root as you can get, plant it about 9 inches deep keep cool and shaded and well watered most will then grow roots and grow strongly. THIS MAY NOT WORK IN ALL REGIONS OR MAY NEED TWEEKING.