Q. What fruit trees can be grown in containers?
Growing fruit trees in a container is more a case of matching the container size to the tree size. It becomes impractical to put a large tree in a container, since the container size would be too large to handle. Most fruits have varieties or cultivars that are small enough to grow in a container that is reasonable in size. Look for dwarf cultivars. Some fruits trees are not very large and can be grown in 3 foot wide and deep pots. If the mature tree's height and width is twice the height and width of the container, chances are that it will grow well if the container is watered well and gets enough light.
Many fruit trees have cultivars that fit into a pot that is five gallons in size. Look for the varieties you want in the catalogs from growers who specialize in fruit trees. Also, you can start off with a smaller pot and repot into larger pots as the tree grows. Many citrus plants can be grown in ten inch pots. Citrus plants need to be protected from the cold in winter.