When can you put tomato starts into a coldframe?

[lakelady]

I'm overrun by tomato seedlings indoors. I have a small cold frame I purchased this year that right now has lettuce seedlings in it. I'd like to move some of the tomato seedlings in soon, anyone have an idea of when that is possible? It is still cold, but I'm hoping soon!

[ddsack]

I would say you can put them out anytime, providing they won't freeze in the cold frame at night. You can keep an old blanket or something to throw over the cold frame to trap extra ground heat at night, even if it's not going to freeze if you're worried they may get too cold.

I put a pop-up cold frame on my upper deck to put my flower seedlings out during the day, but I have to take them in at night because our temps are still far below freezing, and with drafty open boards under it, there is no heat retention like you get on bare ground. It's just amazing how fast the cold frame heats up relative to air temps, even on cloudy days. Venting hot air can be a problem also. Do you have an indoor/outdoor thermometer that you can put out there to check on the temperature ranges? Beats having to go out multiple times a day. (Be sure to position the sensor out of direct sunlight.) I have my base unit in my living room where I can check it whenever I walk by. Don't remember where I got my unit, but I see they have various models on Amazon, from around $20 and up, depending on the range you need. I try to get all my seedlings into natural sunlight as soon as I can after they sprout. Which has meant carrying trays in at night, since our night temps freeze regularly until after mid-May.

[bughunter99]

Originally Posted by lakelady

I'm overrun by tomato seedlings indoors. I have a small cold frame I purchased this year that right now has lettuce seedlings in it. I'd like to move some of the tomato seedlings in soon, anyone have an idea of when that is possible? It is still cold, but I'm hoping soon!

I'm in the Chicago area-5B. I have mine out there now. I have an incadescent light bulb in mine to keep temps slightly warmer if daytime temps are below 50 and it is not sunny. If my nighttime temps were to fall below 29, I would bring the plants inside. They would probably still be OK but I try and keep the stress levels down for them.

Stacy

[lakelady]

I don't have any sensors for it. It is just sitting over the soil in what I call "the old garden". I took one extra seedling and put it in there with the lettuce and such to see what happens. The past few days have been really warm (it hit 80 today!), so I left the lid propped open on both sides. I'm sure very soon I can put all of them out there, or at least most and feel okay with it about May 1st without worries . I really should get a self venting lid though and make my life easier!

[RebelRidin]

Originally Posted by lakelady

I don't have any sensors for it. It is just sitting over the soil in what I call "the old garden". I took one extra seedling and put it in there with the lettuce and such to see what happens. The past few days have been really warm (it hit 80 today!), so I left the lid propped open on both sides. I'm sure very soon I can put all of them out there, or at least most and feel okay with it about May 1st without worries . I really should get a self venting lid though and make my life easier!

Be very vigilant with your venting in the daytime. It is only a matter of minutes on a warm sunny day to go from warm and cozy to deathly hot! Better to err on the side of caution, vent liberally and be a bit cool in the day.

I speak from the experience of not having done so...

[lakelady]

You know, I think I fried some lettuce seedlings in there ...oh well. warm enough now to probably just set them in the garden. Long range forcast looks pretty good. Mild, but cool. The few really hot days we had are thankfully, not staying. It's too soon!

Yes I think putting them out there and just popping the lid open every morning would be best, I like the idea of cooler rather than fried tomatoes