You know those giant plastic containers that hold like 2 gallons worth of assorted snack mixes? Bare root your plants, put them in one of those things and pack in your luggage. Anything that won't fit constitutes a carry-on unless you send it home by mail.

On a trip home from AZ to WI, I packed my plants, but another lady on the flight brought 2 tomato plants right on board with her.

Nancy