Apple trees generally require another apple tree of a different variety to be growing nearby for cross-pollination. Some apple trees, however, are known to be self-pollinating, producing fruit even when there are no other apple trees close enough to pollinate them.
The Home Orchard Society (an organization dedicated to home fruit growing) and heirloom fruit tree nurseries list dozens of varieties of self-pollinating apple trees, including dessert, cider and fresh eating types.
Many delicious heirloom dessert apple varieties are self-pollinating, so you can grow a single tree and produce ample fruit for your pies and crisps. The dessert type apples tend to be smooth, with a dense, fine-grained flesh and a sweet-tart flavor that goes well with cinnamon, cardamom, and flaky pie crust.
Dessert apples often store well, and may be baked even if they have started to soften mid-winter. Keepers Nursery, an heirloom fruit tree purveyor in England, lists Sunset as an aromatic, mid-season Cox-type self-pollinating dessert apple; the St. Everard and Scrumptious varieties for early-season self-pollinating dessert apples; and the market favorites Granny Smith and Braeburn as late-season self-pollinating options.
Fresh-eating apples are crisp and sweet, with a skin that snaps when you bite into it. Apples grown to be eaten fresh may not last as Empire, Gala, and Jonathan varieties are also great snacking apples which the Home Orchard Society advises are partially self-fertile; the will bear fruit if planted as a single tree, but will increase their yields if another apple variety is within a few hundred yards of their growing location.
Cider apples are juicy and tart, more suited to the press than for fresh eating or dessert baking. There are a few heirloom cider type apples considered to be self-pollinating. Among them, Home Orchard Society lists Beakwells Seedling, Kingston Black, and Michelin for U.S. growing, where cider is usually a non-alcoholic soft drink with a unique sweet-tart flavor.
The Keeper's Nursery--located in England, where cider making more popularly means hard cider--recommends Brown Snout and Dabinett as self-pollinating cider apples.