United Kingdom 
I have a plum tree sapling in a pot about 4foot tall which has been grown from a plum stone. If I keep it in the pot, thereby restricting its roots, will it eventually flower and fruit or must it be planted in the garden?
19 Jun, 2016
Answers
theoretically it should be restricted but the number of blossoms and therefore plums will be seriously reduced. it will be better in the ground.
19 Jun, 2016
And, unfortunately, given that it has been grown from a pit there is no guarantee the plums will be edible.
19 Jun, 2016
It should be possible to maintain it in a pot by using bonsai techniques, even if you don't care if it has a "bonsai shape". On the other hand, that would involve regular, skillful, and frequent attention to pruning and feeding. Also, it will need careful root pruning and soil renewal every few years. Fruiting will be limited, though they will probably be edible, if not necessarily very large or nice and sweet--most likely good for preserves, only. It may not be worth the effort, unless the challenge attracts you.
21 Jun, 2016
Hi there. You really need to plant it in the garden. Only fruit trees grown on dwarf rootstock will be happy in a large pot.
19 Jun, 2016