Mine are all outside for several days now with no protection at all. Before that they were in and out of hoophouse with some outside exposure.

My question is whether I should cut back on the lighting during the day.

There is no correlation between reducing light and preventing leggy plants. Just the opposite in fact. A green house provides much more natural (and artificial light) than you can do in a house. Do their plants get leggy?

If your plants are already 12" tall then the issue is simply starting them way too early. And if you have 3 weeks till plant out then simply cut off the growing tips and root the cuttings so you'll have healthy size transplants when the time comes.

Dave

I would say : keep them in much cooler place, like 55F.
In cold weather tomatoes grow very slowly. I have couple of small seedlings out side. After 3 weeks they are not even 3" tall. My planted out tomatoes (37 days ago) have been growing at less than half the speed that were growing inside under light.

Other things you may choose to do:
-- Stop fertilizing
-- water spaingly ( let them get dry, blue and black )
-- prune the foliage as much as possible/practical.
-- When the time come to planting, plant much deeper or trench them.

Dave, if I cut the growing tips and root them, do I put them under the lights? I read somewhere not to put them under lights for a couple of days. What else should I bee doing?
Thanks, Sharon
Ps as you can see I am new to this!:)

Am not Dave, but have done following, stick top of tomato deep down the pot, water well but make sure there is decent drainage still there. It is easy to create damping off with too much water. Air is a must. Misting tops frequently helps as they going to be wilting a bit.

Lots of posts here about all the how-tos of rooting cuttings the search will pull up with all the details. Linda covered it mostly. I don't mist tho. Don't like wet leaves.

Basically it is pots/cups of thoroughly wetted potting soil. snip off a 6" long grow tip, trim it up to have bare stem and no heavy leaves hanging, stick deep into the pot and lightly press soil around stem, shade until it perks up (2 days), water to keep soil moist, then treat as normal plant.

Dave

Thanks Dave and Linda. Will try with a few of the taller ones. In the meantime, I relocated my plants to another room, which has good light, but not ceiling to floor windows and much cooler, especially with the windows open and the cool winds. It was almost like being outside. We are looking at some cool but sunny weather, so I'd like to start bringing them out iin the shade tomorrow. Too soon for zone 5b?

mmm, why too soon... I mean tomatoes can linger outside as long as they have to til they get planted. As long as you can drag it back or in garage if the really bad weather strikes at this point I would not bother to keep lights going in zone 5. But thatôs me. 2 weeks of hardening is something I aim for.