Read topics on hardening and finally got to take my plants out. cukes, peppers and tomatoes I read 60 degrees but we hit 58 out with a little breeze so I decided to go for it. They aren't in full sun but rather in the shade from a tree. Hope I'm not pushing it. Opinions
I'm just learning on hardening plants off and I start with them next to the house with a little morning sun. From there I move them further from the house or into a more sunny place. Found that noon and early afternoon sun is a really killer on new plants and a breeze can be really hard on them at first. Some other plants I've been putting a fan on them to help with that and so far it seems to be working.
Sounds like ya'll have the idea of hardening off spot on. Introducing the plants to the outdoors a little at a time...a little filtered sun here, a little breeze there..and don't be too concerned about temps in the mid 50's..
Upper 30's..yes..it stunts the growth, which isn't a bad thing if the plants are growing too quick before transplant time...it just slows them down.