Not sure the answer you want :
http://pe.usps.com/text/imm/fh... Restrictions: Plants, seeds, bulbs must be accompanied by plant health certificate.
I tried to locate what or which Plant Health Certificate you would need and ended up here :
https://www.aphis.usda.gov/aph...
Never did find the document ...... just feels like trying to find one grain of salt on a white beach
