What is the lowest temp. in ohio that it is safe for annuals to stay outside?

It is a mix of flowers. Some million bells, some petunias, and a few others like those.

What is the lowest temp. in ohio that it is safe for annuals to stay outside?
Hello, from the Upper Peninsula of Michigan.





55 degrees F, ambient air temperature.


50 degrees F, soil temperature.





When in doubt, after they're planted, cover even with newspaper to avoid cold temperatures.





Although they will survive some cold, it'll stunt growth %26amp; they'll delay growth, so protect the little beauties.
Reply:millionbells and petunias can both handle frost but not a hard freeze unless they have been out there a long time.


if they have been grown in a green house this spring you need to harden them off(protect from temperatures below 45 degrees)





what other plants do you have, i can help you figure out how much they can take.
Reply:Location is irrelevant as long as you plant them after any possibility of frost has past. Average time here in Indianapolis for the last frost is April 15th...
Reply:hmm, if things are going to be 40 and below, it would be safer to cover them