Problem slightly different

[jwr6404]

I have 60 seedlings of 20 different varieties. One of the varieties is Stump of the World(4ea). All the SOWs leaves are turinin Yellow along with 1 Big Zac. The other 55 plants are doing fine. They are in an upstairs room under lights 24 hrs per day. The lights are 1-2 inches above the pot The temperature runs between 65 degrees(night) and 74 degrees day. All are in the same type,16 oz container. Question? Do I have any need to worry? I do want at least 1 Stump.

[nctomatoman]

24 hour a day light is too much - when mine are under lights, they go from 8 AM until about 8 PM. Also, get the yellowing ones some gradual sunlight on nice days. Tomato seedlings don't enjoy being under lights for too long - the fresh air and sun really helps them to be healthy.

[jwr6404]

will turn the lights off at night beginning right now. Still to cold to put outside now plus here in the PNW this Time of year NO SUNSHINE

[nctomatoman]

Yes, we lived in Seattle for a year, so indeed do remember - sunshine is scarce at this time of year (though I think we were lucky - it was not as nearly a rainy year as we feared it might be)

[dice]

I left a tray of seedlings out from around 11:00 am to 7:00 pm
today (cloudy day, no wind, no sunburn risk, ran out of space in
the coldframes). They looked fine when I brought them back in.

They probably do not grow much at 50F on a cloudy day, but
they do not particularly suffer either, and they do get a little
hardening off done.

Just check the weather first (don't want to drown them or fry
them), and keep an eye out for sudden changes. Worth a try
with plants that are struggling anyway.