HI Msbumble,
Last year I found a shooting star at the supermarket as well. I repotted and kept it inside (I'm in Texas and the heat during the summer is unbearable) next to a door where it would get sunlight but also get the warm air. I made sure to keep the soil moist. Last fall I planted in the ground, mulched during the winter and now it is twice as big and is blooming.
I think yours will do fine in the pot into you plant in ground. Make sure to keep the soil moist also make sure it is shaded or gets only AM sun.

Hope this helps out a bit.

Thanks for your reply. Do you remember if you had the tight mass of roots I described? If so, what did you do with them?

If you found this offered as a florists type plant and not a nursery, you should acclimate it to real sun and wind more slowly, somewhat like you would harden off an annual. Don't thrust it out into the real world all at once, give it a little time to acclimate.

Do what you must to loosen that rootball. If you can't loosen it with your fingers, cut into it in a few places with a knife. If planted with the roots still circling in that pot shape, it will never reach out and establish into surrounding soil.