I have seedlings that are 4-6 weeks old. It has been unseasonably warm and they have spent much of their time outside in the past week or two. I am wondering how chilly they can handle being outside, it is dipping into the mid- to high 40s overnight in the upcoming days. And would it be more beneficial to take them inside even if they can handle it?
Spring Seedlings Outside
Certified GKH Gardening Expert
Most plants require temps to remain at least a consistent 55-60 degrees F. before planting them outdoors. This does not include hardier crops, like lettuce or most root crops, however. Since you're experiencing temps in the 40s, I would give it more time before putting them outside. When it warms up enough and they're ready to go outdoors, I would recommend hardening them off first. This article will help with that: https://www.gardeningknowhow.com/garden-how-to/seeds/how-to-harden-off-your-seedlings.htm
As long as it don't get below 60 degrees, tomatoe s can not take any cooler.