National Clean Plant Network

Roses, major horticultural display attractions at public gardens, have a new ally. The National Clean Plant Network, a program of the United States Department of Agriculture supported through the Farm Bill, recently added roses as the first ornamental commodity crop.

The National Clean Plant Network – Roses (NCPN-R) will focus on providing high-quality, virus-tested rose stock to serve the needs of propagators and breeders within this specialty crop industry. This in turn will benefit public gardens which rely on growers to supply roses clean of serious pathogens and pests for their displays and collections. Roses are popular with visitors, and many gardens rely on earned income from renting areas planted with roses for weddings and other functions. Gardens struggle to maintain these displays while facing labor shortages and introduced pathogens such as rose rosette disease.

A multi-disciplinary advisory board for NCPN-R has been established with representatives from the growers industry, university-based research and extension faculties. Pam Allenstein, the Association’s Plant Collections Network Manager, was elected to represent the public gardens sector. The board met in June 2016 to determine a list of targeted pathogens and to establish protocols for combating viruses that have a negative impact on the rose industry. Next year’s meeting will be held at Huntington Botanical Gardens.

Foundation Plant Services at UC Davis is currently conducting virus testing and elimination for roses. This clean stock rose program begun in the 1960s by Dr. George Nyland, is the largest in the world with 548 cultivars and 2372 plants. Researchers at Texas A&M Plant Disease Clinic are developing improved diagnostics to efficiently test for multiple viruses at the same time. Support through NCPN-R is expanding the clean rose collection to include popular old garden roses, key miniatures, and other significant rose cultivars. Public gardens are encouraged to seek out nurseries committed to using virus-tested propagation stock and managing their sites to keep roses clean through the pipeline.

Two Nationally Accredited Rose Collections™ are held by Reiman Gardens at Iowa State University and Montreal Botanical Garden.