where are you ...

cold damage short of freezing solid.. can take some time to show.. especially when its relatively cold outside ... as compared to say... if it went up to 80 the next day ...

i dont know how much effort i would put into trying to winter it over a buck 98 plant... but what the heck.. throw it in the garage.. whats to lose.. you already got your monies worth ...

ken

I leave mine to die in the pots outside and they reseed and I get more petunias next year. I have been doing this for the last 4 or 5 years. I am in central VA.

Petunias in their natural habitat are perennial. So it could well survive the winter in a frost free place. But I'm not sure it's worth the bother other than as an experiment.

Petunias are very cold tolerant and in the deep south, are often found in the garden centers for fall planting. So it's not at all unsurprising that your plant is still green.

But, it won't take kindly to living in the garage. Best to treat the petunia as an annual and start again in the spring with pretty new plants.

Wind chill is a measure of how the air feels on skin...nothing to do with plants. A desiccating wind may have done the blooms in, although most petunias look quite tired by now regardless of temps. Can you overwinter it in your garage? Ken's first question is the key...Where are you?

tj

I'm with floral_uk; it might survive if your garage doesn't fall into deep freeze over the winter. But why bother, except for the experiment? I like to run experiments for the fun of it sometimes, but otherwise - let nature do it's thing.