Some categories of seed for planting are prohibited entry into the United States. These seeds may only be imported into an APHIS-approved containment facility under a controlled import permit (PPQ 588–Permit to Import Prohibited Plants or Plant Products for Experimental Purposes) for research, development, and therapeutic purposes.
NAPPRA is a category of regulated plants that cannot be imported into the United States until APHIS completes a pest risk analysis and puts mitigation measures in place. Small quantities of NAPPRA plants may be imported for experimental, therapeutic and development purposes under strict quarantine conditions with a controlled import permit (PPQ 588–Permit to Import Prohibited Plants or Plant Products for Experimental Purposes).
Some plant species from a few countries are exempt from the NAPPRA restrictions based on pest risk assessment and trade history. Please refer to APHIS’ Plants for Planting Manual or the NAPPRA site (see the NAPPRA Lists section) to view lists of NAPPRA plants and country exemptions. Seeds from a country with a NAPPRA exemption may be imported with a PPQ 587–Permit to Import Plants or Plant Products and a phytosanitary certificate from country of origin.
Seeds of Federal Noxious Weeds are prohibited from all countries. These seeds may only be imported for research in an APHIS-approved containment facility with a PPQ 526–Permit to Move Live Plant Pests, Biological Control Agents, or Noxious Weeds.