My garden is actually very small, so about five years ago I gave up on regular species of trees and started with the dwarf varieties.
This dwarf lemon is around four years old, and treated very badly indeed. It is water-stressed over summer and has only just fruited for the first time.
My gardening philosophy is that if a is plant hardy enough to handle where it has been planted, it gets to stay. Harsh, but it means that I spend very little time cosseting my plants like they are sickly infants, and generally if something takes in the garden, it is very well suited to where it is.
(Of course, I do do a lot of handwatering and fertilizing at the very start to give it the best chance of taking… )