Plant it in at least a one gallon pot ASAP. Then put that pot in partial shade for a few days. Then put the pot somewhere where it will not get so hot that it fries the baby rose - depends on your weather, etc. I tend to put mine on top of the soil in huge pots where other things are growing, so they are not sitting on hot pavement. Be sure to protect it from deer & other critters.

I leave mine in the one gallon pot for at least 6-12 months. Perhaps you should wait until next Spring to plant yours into the garden.

Jackie