If you ever wanted to have fruit trees but your garden is too small, don't let that stop you. The magic of grafting can give you multiple varieties all on one tree.
There are several ways to graft 'scions' which are small twigs of the desired variety onto the rootstock.
One method that I've tried is to use a method where the pencil sized scions are treated just like a pencil, and sharpened with a knife or a very sharp pencil sharpener, and a hole the same size is drilled into the stem of the tree.
The beauty of this is that you can take a new variety and place a branch exactly where you want it. In the case of a mishapen or damaged tree, grafting new branches to take the place of missing ones is the perfect way to get a head start on the fruit - why wait for years for a new sapling to grow up when you can use an older tree that might produce fruit in a year or two?
These trees are also called fruit salad or fruit cocktail trees, and most are grown on dwarfing rootstock, making them a good choice for growing in a barrel or container.
There are many options such as stone fruits like plums, nectarines and peaches grafted together so they ripen at different times. Apples varieties that ripen to different colors, and even different citrus fruits can be used.
The beauty of these multi variety trees is that the branches can be placed exactly where they will get the best light and air. Just remember not to prune them off by mistake.