When can I put my seedlings in the cold frame?

I've got seedlings that just made their appearance this weekend (marigolds, tomatoes, african daisies, etc.). They were planted in peat pots and are in flats. I have a cold frame situated on a stone bed on the south side of our pool house. When will I be able to move these to the cold frame? I've never done this before, and I don't know what the minimum/maximum temps should be for young seedlings.

I would do it when they are showing several true leaves and the nighttime temps are around at least 40 degrees. You can cover them with a blanket (if you can support the blanket a bit so it doesn't weigh them down, thats good) even in the cold frame. Make sure it doesn't get too hot during the day in the cold frame. I think in Ohio, you may have a bit of a wait :)

I don't have grow lights, so my worry is that now that they've sprouted, they won't get enough light.

then bring them out during the day into the cold frame and bring them back in at the end of the day. It's a pain, but they will get leggy if they don;t have good light.

I thought of that...

I wouldn't mind doing it, really. I've only got four flats.

You can buy a heating cable for making a hotbed. Get a peice of plywood the size of the bottom of your cold frame. Drill holes for drainage, and staple the heating cable on it. These heating cables are made to keep your flats warm at around 72 degrees. Does not matter what the air temperature is, as long as the soil temperature is at 72 degrees you will be fine. Check out : http://www.charleysgreenhouse.com/index.cfm?page=_search

They have different size heating cables. Good Luck!

I don't know....she/he is in Ohio, they just had a snow storm, and if the air is well below 32, the dirt may not freeze, but the foliage will. I would wait until the nighttime temps are well above freezing. Seedlings are fairly tender. Maybe if the foliage is covered well with blankets.

I'm in northwest Ohio, and we didnt' get any snow. That was in the southern part. It's 47° here today, and the forecast says we're supposed to be in the 40s and 50s from here on out, with lows at night in the high 20s to mid 30s.

It takes approximately a week for the seedling to get use to the outdoor temps in any location. So its good to only gradually bring the plants outdoors. I would recommend bringing them out only a few hours the first day . The next day a few more hours. Also its good to filter the sunlight especially if it a very bright day. Those little tiny seedling aren't quite use to full intense outdoor sunlight.Be careful . Let the plants have fresh air periodically but only gradually do this.
I hope this helps. Frankford

Thanks, Frankford! Will do!