I'm in Syr NY and my peonies are done blooming, I want to take some across country on an airplane, what is the best way to do so?
Peonies are best moved in late fall or early spring. For now, cut them back to about 6 inches, wrap a large rootball in plastic to keep from drying out, replant asap, and expect them to look terrible for the rest of the year. They may not bloom next year either due to transplant shock.
And when you replant them, bury them very shallow, with the bud just even with the soil. Keep them nice and damp, water as needed.