Apples are dwarf to semi-dwarf trees that grow no larger than approximately 5m/16' tall. Size can be controlled by pruning in very early spring. Grafting into a semi-dwarfing rootstock affects the overall size of the plant only, not the fruit produced.
Apples are self-sterile and require a second variety for pollination. Click above to see the chart showing which species can be used to pollinate another.