I put 3 nice little tomato plants into my greenhouses late last year, I think around early November. They were "leftovers" at the nursery for fall tomatoes.
Put each one in a 3 gallon pot with a cage. I was _hoping_ to get winter tomatoes but that did not happen. :-P Even with a light in there, I guess they "know" when it's really time to bloom!
Well, they are about 3' tall now and I've never seen such lush foliage! They look wonderful, and started blooming 3 weeks ago. I've been going in there and hand fertilizing them, but I have to get them at just the right stage I guess. ;-)
Just checked and I have 4 nice little tomato sets, and more blossoms that I just went in and pinched.
I'd like to eventually try hydroponics, but I need to study up on it!