The hole when dug should be twice as wide as the size of container, but no deeper, as this may cause burying of the crown as the soil settles. Simply scoring the bottom of the planting hole will aid in directing roots to the deeper subsoil. Whether in a root ball or a container, you want the soil level in the container or on top of the root ball to be flush with the plane of your existing soil. The important element is to not bury the original crown of the tree. That must be above the soil level to keep it from rotting. When planting, it maybe necessary to amend the soil in order to increase moisture retention or to increase drainage. In order to help the common clay soil hold water, it is good to add some topsoil, peat moss, or organic compost to the hole. A good 2-4” layer of mulch is recommended as fruit tree roots do not like competition from weeds and other plants. Most fruit trees require another pollinator in order to bear fruit. This means you need 2 different varieties. Concerning apple trees, flowering crabapples that bloom at the same time as a fruiting apple tree will pollinate it with no effect on the apple’s fruit. Some trees are listed as self-pollinating or self-fertile means they are capable of bearing fruit by themselves. Productivity may be enhanced by having another variety, however, this may not be desired for varieties prone to overbearing.