What you do with your 2012 tomato plants depends on how concerned you need to be about tomato diseases. I may run the tiller over them but usually do nothing other than try to get them against the soil once they are frost-killed so that they begin to decompose. I've been known to show up out there with the lawn mower set up high
Starting the 2014 plants? I go for too early and tolerate the bother. Twelve week old plants are usually what I set out after I've removed any green fruit that may have gotten a start in the greenhouse. Really, I should "up-pot" them to 6" but have them in 4" pots. There are space problems
in the greenhouse after awhile. Staking in the pots with bamboo then setting the plants out deep enuf where more roots can grow from the stems, helps.
. . . just what i do . . .