I've lived up here for 30 years now, and I always wait till after Memorial Day to plant anything that is frost-tender. I remember one Memorial weekend, many moons ago, that we went to the yard sales on the Saturday in shorts and tank tops. That night a storm blew in, and we got quite a bit of snow on Sunday. You never know up here, but I don't want to waste the time and the $, only to have to start all over.