patio fruit trees

I have a Stella but it is in the ground and after 4 years it is a big tree. The size of the tree depends on the root stock and 3x2m looks compact. Need to keep it pruned because fruit grows on old growth, so it should not get out of hand. (like mine has) Also you don't need a pollinator. Need very little maintainance.
You will need a netting system because the birds will have them.
There are 'large' pots but think of the plant in 4 years time. You may need to grow it in a water butt.
£10 for a fruit tree is a good price and this is something you will have to do to find out.