I have a Bearss Lime Tree in a container which we keep outside during spring & summer. We've had it over 2years & it's doing exceptionally well. I am in zone 6 with very sandy soil. There is someone a couple of miles away with 2 mature lemon trees on their property, can I put my lime tree in the ground?
You would probably have to provide major protection for it in winter-- maybe even bulid a shelter over it and add some heat. You are probably better off keeping it in a container.
it's not hardy in zones lower than 8. i wouldn't chance it - even with protection. if you have a heated greenhouse that is kept at temps above 60, then you might be able to keep it going. still, i really wouldn't chance it...even one day of no heat in the middle of winter (say if the power goes out from a storm) would kill it. best to keep moving it back inside for the winter!