I sprout lettuce in the house for the even 70-75ðF temperature, which lettuce seems to like. It goes into the GH (min 55ðF) when the first true leaf has a recognizable shape, which is several days after you can first see it. Been doing it for years with good results. I'm in a warmish zone, so can afford to keep the GH relatively warm. If you're in a coldish climate, you may need a different routine.

I start tomatoes, chard, peppers, herbs, you-name-it in the GH on heat pads set at 75ðF soil temp, inside one of those little cheap plastic 4-shelf "greenhouses", under the plastic cover when the GH air temp is less than 65ðFñ. With the cover on, the heat pads keep the air temp in the little GH around 65ðF when the big GH is at 55ðF. Again, I'm in a warmish zone.

I don't grow tomatoes to maturity in the GH. I do sow seed in February as described above, then transplant to 5" pots kept in the GH at min 55ðF until outdoor night min is expected to be consistently above 45ðF. Then out they go onto a concrete pool deck until ready for final transplant. Once again, I'm in a warmish climate.

Thanks for the info! I am in a much colder zone then you. I used to live in Tacoma..I miss it for the growing I was able to do.