Just put one in the ground, bare root and well watered. Hoping it will survive the winter and grow in the spring. I live in east-central Ohio (zip 43022). We've had our first killing frost this past week but the ground is still soft. What are my odds? I am an amateur lepidopterist and have fantasies of getting Giant Swallowtails here.
I think your odds are very good. Trees are best planted in the fall. If you have a dry winter, be sure to irrigate it about once a month. You can increase your number of Giant swallowtails by planting the herb rue (Ruta graveolens), which is also a host plant. It is hardy to zone 4 so should do fine during the winter. Mine seem to die out after a couple of years but I know others who have it for a long time. I also grow common prickly ash, Zanthoxylum americanum, and I always get caterpillars of the Giant.