Last spring we had a late frost. I'm a always a good girl and wait to plant my pots until after May 15th in our zone 5 climate. Once they're planted I listen to the weather forecast very carefully until we're safely into June.
Late last May, for the first time, I found myself gathering all the pots together in the protective shelter of a corner of the patio. I covered them with old sheets at night and uncovered them during the day.
I'd never counted them, and didn't realize I had more than 4o pots on the patio and on the front steps. And of course, since they'd just been planted, they were well-watered, and hea-vy.
I left those 40 pots in that corner for more than a week. I made good and sure when I moved those babies the next time, it was gonna be the last time.