Harvest times depend on the varieties. I think Trudi labels them with a DTM guide. That tells you the number of Days to Maturity from the time you plant them out. We still have lots of time here in zone 7. I'm going to start another batch to replace my determinate varieties this week. I also prune off the suckers and root those for planting out in early July.

Mine have been in the ground since Easter. I've lived through 2 frost warnings now with no problems, but no frost either. Last night it was 39. I'd say get them in the ground. Bury them all the way to the bottom of the leaves so they can root along their stems. Fertilize with a 10-10-10 2 weeks after that. Make sure you keep them watered. Consistent watering is key with tomatoes.

Save seeds, and enjoy. :)