Tomato plants wilting after first night outside.

[NewCanuckGardener]

Hello everyone! Newbie gardener here. I live in central Alberta Canada, Zone 3. I am in the process of hardening off my plants, and last night was the first night I left my plants outside overnight (in a greenhouse) the temperature got down to approx 4C. when I opened the greenhouse this morning (it gets morning sun) it was already nearly 22C in there. Most of my plants seem okay but my sunflowers are wilty, and mostly, my tomatoes - they are bent nearly in half! They are in peat pots currently, in a tray that also has dirt(because there were so many roots growing through the pots!). The soil is very moist. I'm hoping there is something I can do to save them! They were my strongest, healthiest looking plants up until this morning.

Any advice is greatly appreciated!!
Thank you,
Lori.

[NewCanuckGardener]

Well, in just an hour or so, it seems as though the plants are perking up, but now my watermelon and cucumber seedlings seem to be droopy, where they were quite perky an hour ago. I'm really not sure what to take from all of this! I guess I will just wait and watch as the day goes on.

[applestar]

I think tomatoes might have been a bit cold. It's normal for cucurbits to get droopy in the heat of the sun.

Take lots of notes -- check temperature (do you have a max/min thermometer in there?) and humidity, try hefting the containers to make sure they are not getting dry. That's realiy the only way. Remember though that shallow containers with actively growing seedlings will dry fairly quickly in the heat.

[NewCanuckGardener]

Thanks applestar! I think watering must have been the issue. The plants did much better last night, and with a nice long stretch of warm evenings ahead I decided to go ahead and plant nearly everything! Could be a giant newbie mistake - it was so hard to wait any longer! Time will tell, I suppose!