In the efforts to prevent a quarantinable strain of Ralstonia from entering the United States, USDA-APHIS has changed importation rules for rose material for planting. This includes rose material coming from Canada.
Under the new federal order, roses (Rosa spp.) grown in Canada must now have been grown entirely within Canada or the U.S.. This includes root stock and graft material.
This is to reduce a potential pathway for Ralstonia solanacearum Race 3 biovar 2 (Rs R3bv2) into the U.S., which can devastate solanaceous crops such as potato and tomato, as well as geraniums.
Read on for more details about RS R3bv2 and the new export regulations.
What is Rs R3bv2?
Rs R3bv2 is a strain of bacterium of Ralstonia solanacearum that is particularly pathogenic, causing vascular disease of a wide variety of plants. Other races of this bacteria are endemic to the United States (Race 1) or are specific to hosts not grown in North America (e.g. bananas), and are not considered a severe threat.
R3bv2 (also referred to as R. solanacearum phylotype IIB) is not established in the U.S. or Canada, but is known to infect solanaceous plants (including potato, tomato, eggplant and pepper) in other countries. It is a quarantinable pest in both the U.S. and Canada because it poses a severe threat to many crops grown here. (Fun fact: it was listed as a potential bioterrorism threat in the U.S. Agricultural Bioterrorism Act of 2002).
Why Are Roses Suddenly Being Regulated for This Pest?
The major ornamental host for Rs R3bv2 is geranium. Both the U.S. and Canada have programs related to import/export of pelargonium plant material to prevent the spread of this disease from potentially infected geranium cuttings into the broader environment. This was due to the identification of Rs R3bv2 in geraniums in greenhouses in both the U.S. and Canada in 2003.
Recently, roses (Rosa spp.) have been identified as an asymptomatic host of RS R3bv2. This means they don’t show typical symptoms of bacterial infection with Ralstonia, but can still carry and transmit the disease, or show symptoms at a later date (latent expression).
Because of this recent discovery, the USDA-APHIS has added restrictions on the import of rose material into the U.S.
What Are the New Regulations?
To export rose plants or material to the United States, the following must be adhered to:
- All plant parts (including rootstock and graft material) must be solely grown in Canada or the United States, AND
- Shipments must be imported under the U.S.-Canada Greenhouse-Grown Plant Certification Program (GCP), OR,
- Shipments must be imported under the Canadian Nursery Certification Program (CNCP), OR,
- Plants grown outside of the GCP or CNCP must be accompanied by a Canadian phytosanitary certificate for export
The restrictions apply to ALL plant parts intended for planting, except for seed.
Note that cut roses are excempt from these restrictions.
Previously, Rosa spp. were into the United States without any specific safeguards against Rs R3bv2. The new regulations went into effect yesterday, May 20th, 2026.
More Information
You can read the full U.S. Federal Order here.
You can find a list of symptoms and pictures of this disease here.
Please contact your local CFIA office if you have more questions regarding phytosanitary certificates or joining the GCP program.