Hi Della,
Have you gotten your answer yet? If not, try contacting the Animal and Plant Health Inspection Service (APHIS), which is an agency in the United States Department of Agriculture. APHIS issues phytosanitary certificates for this country, so you should be able to find your answers through them.
http://www.aphis.usda.gov/wps/...
And the FAQs about APHIS's phytosanitary cert program are here:
http://www.aphis.usda.gov/wps/...
Good luck!