Catalogs & suppliers

Buying plants and seeds across borders and state lines: USDA and state rules explained

Catalogs & suppliers · Published 2026-10-24

A seed packet or a rooted cutting looks harmless, but plants are one of the main ways pests and diseases travel. That is why the US regulates plants and seeds moving into the country and, in some cases, between states. Most gardeners buying from domestic nurseries never notice these rules; anyone ordering from abroad, or ordering certain plants across state lines, needs to know them.

Buying from another country: you are the importer

According to USDA's Animal and Plant Health Inspection Service (APHIS), a person or business in the United States that buys plants for planting from another country through an e-commerce site is considered an importer. That has practical consequences:

• Permit. APHIS states that most plants and seeds for planting require a PPQ 587 import permit, applied for through its eFile system; only US residents can apply. If a permit is required, you send a copy to the seller.
• Phytosanitary certificate. The seller generally needs a certificate from the plant protection organisation of the exporting country, attesting that the shipment meets US requirements.
• Labelling and routing. Where the permit requires it, mailed shipments carry a green-and-yellow APHIS shipping label and are addressed to an APHIS plant inspection station at an approved port of entry, with an invoice listing scientific names and quantities.
• Exceptions. APHIS lists items that do not need a permit, such as shipments of 12 or fewer plants when no specific restriction applies, most plants from Canada, and most herbaceous seeds, but other requirements may still apply. Some plants and seeds have special requirements or are prohibited altogether, including seeds of federal noxious weeds.

Websites that are not what they seem

APHIS has found that some websites that appear to be based in the United States are in fact operated overseas, so a seed order you thought was domestic can arrive as an international shipment without the required documents. It reports that seeds from sellers outside the US may not meet import requirements. Look for a physical US address, check where the order ships from, and be wary of very low prices on rare plants.

Unsolicited seed packages

In 2020, people across the United States reported receiving packets of seeds they had not ordered, sent from overseas. USDA asked recipients not to plant them, to keep the seeds and packaging, and to contact their State plant regulatory official or APHIS State plant health director. APHIS officials believed the packages were linked to a "brushing" scam, in which sellers send cheap items to post fake reviews. The advice still stands: never plant seeds of unknown origin.

Moving plants between states: federal quarantines

Within the country, APHIS can restrict the interstate movement of plants from areas under federal quarantine for a serious pest or disease. Citrus is the best-known example for home gardeners: to slow the spread of citrus greening (huanglongbing) and its insect vector, the Asian citrus psyllid, APHIS restricts the movement of citrus plants and related host plants out of quarantined areas, which have included Florida and parts of other states. In 2025 it established a statewide citrus greening quarantine in Mississippi after the disease was found in samples from residential properties.

In practice, this means a nursery in a quarantined area may not be able to ship citrus trees to you, and you should not carry citrus plants or cuttings out of a quarantined area yourself. Reputable nurseries know the rules and will tell you what they can ship.

State rules

Each state has its own plant health agency and rules for nursery stock coming in from other states. Typical requirements include:

• A nursery certificate or inspection tag showing the shipping nursery is inspected in its home state.
• A phytosanitary certificate where a state or federal quarantine applies.
• Prohibitions on particular plants, for example invasive species or hosts of pests the state is trying to keep out.
• Inspection on arrival: California, for example, requires out-of-state nursery stock to be inspected on receipt.

The National Plant Board, made up of state plant health officials, publishes summaries of each state's rules. As a buyer, you rarely need to deal with the paperwork yourself; a reputable nursery handles it and declines orders it cannot legally ship. But if you live in a state with strict rules, such as Hawaii, California or Oregon, expect some plants to be unavailable by mail.

Carrying plants yourself

The same rules apply when you travel. Plants, cuttings, seeds and soil brought back from abroad must be declared at customs and may be refused entry; within the US, some states inspect plants at their borders or prohibit certain plants. Soil is a particular concern because it can carry pests, diseases and weed seeds.

A simple checklist

1. Buy from domestic nurseries with a clear US address when you can.
2. For plants from abroad, read the APHIS guidance and get a permit if required before ordering.
3. Check your state's restrictions for the plant you want, especially citrus, fruit trees and plants known to be invasive.
4. Never plant unsolicited seeds; report them.
5. Ask your extension office or state department of agriculture if you are unsure.

Plant health rules protect your garden and your neighbours' farms, not just borders.

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