Answer: The foliage on hostas will not tolerate a frost, so they will need to be protected until the weather settles. You could pot them up and keep them in a sunny window until the days are moderate. On days when the temperature is warm enough, set the pots outside in a sheltered location out of wind and in morning sun only (these are shade loving plants); at night when temperatures drop, bring the pots into a location where it will not be below freezing. This seems like a lot of work, but they will not be healthy if you leave them where they are now or plant them outside in the still cold weather.
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