If you are living in a unit and only have a balcony or small courtyard this does not mean you cannot have fruit trees.You can grow the trees as vases and be able to have an orchard in a small space. You can grow the vase whatever height you like but the best size is 3 foot high.If you start with a 305mm.pot and plant your fruit tree in it,then cut the tree off a quarter of an inch above the the first node on the trunk above the graft.Use a straight cut as you need multiple branches to grow.You need six branches so if you do not get this amount cut the new growth at the third node so it grows multiples to get your six.As these new branches reach the outer rim of the pot, put in six 3ft. stakes in the pot around the edge at an angle so the top is wider than the bottom.Make a wire ring around the bottom just above the height of the graft on the tree.Then tie in the top with a larger ring so you have the shape of your vase.Once the branches are long enough take each one of the six and take it under the wire and tie it in place.Once they have grown out enough to have a node outside the wire,cut the branch beyond the node but cut at an angle with the wound underneath so that the new branch grows up the stake.As each of your new branches has 3 nodes make a straight cut above the third one so that it sends out multiples.As these multiples get three nodes repeat the process.As the branches thicken out you can start trimming them so your vase is smooth sided.Once the branches reach the top wire really work the nodes so that you can trim either a square or a rounded rim on your vase.If you are luckey enough to get eight branches let 2 of them grow about 3 ft. beyond the bottom wire and when they are long enough lift them and bend them over to form 2 handles so that you end up with an urn.
Because you have so many branches you will get just as much fruit as you would from a tree,and you are picking fruit from inside and outside the vase in the fruiting season.
When picking your tree get one with the lowest graft possible so that you have no space between the pot rim and the bottom of your vase.