How we Rate our Virus Freer Dahlia Tubers.
Dahlias growers across the United States face challenges from numerous viruses that impact plant health, growth, survival, and flower quality. We are striving to provide you with “Virus Freer” dahlias for your garden.
Our Mission: striving to provide virus free Dahlias
Premium and High-Quality
Premium Tubers:
DCMV/DMV, TSV, and TWSV Excluded
These tubers represent our highest standard of quality. They are classified Premium based on the foundation stock testing negative for the viruses listed below.
Thorough Testing: Foundation stock has tested negative for Dahlia common mosaic virus (DCMV), Dahlia mosaic virus (DMV), Tobacco streak virus (TSV), and Tomato Spotted Wilt Virus (TSWV).
Field Testing: Each fall, approximately 30-45% of the field-grown plants undergo retesting (about 80 of 250 plants). Results for the past two years have been very encouraging: testing for DCMV/DMV found infection rates of only 3.3% and 12% (2023, 2024), for TSV only 1% were infected, and none were infected with TSWV.
Healthy Practices: Diseased plants are immediately removed to maintain clean fields. Cutting tools are disinfected between every plant.
When you choose Premium Tubers, you’re selecting the best we have to offer—Our “Virus Freer” plants have shown higher sprout rates, vigorous and lush foliage with abundant blooms. Keep checking back as we improve our supply of Virus Freer tubers.
High-Quality Tubers:
TSV and TSWV Excluded
These tubers are classified based on the foundation stock testing TSV and TSWV negative.
TSV & TSWV status: All foundation plants are TSV and TSWV test negative before planting in the field (about 50% of all new tubers are positive and have to be discarded)
Field Testing: In the spring, about 30% of previously grown plants are retested for TSV and TSWV (only if suspicious). Any positives are removed from the field.
Healthy Practices: Diseased plants are immediately removed to maintain clean fields. . Cutting tools are disinfected between every plant.
While these tubers probably carry a similar infection rate for DCMV/DMV as most U.S. grown dahlias (~70-95%), they were healthy and robust when grown by me the previous season and are a healthy choice for your garden.
Note that these viruses can be fickle in their symptom presentation, not evident in one season, but showing up the next. Try to reduce plant stressors by always providing fertile soil, ample water, and by keeping insect pressure low. Learn more about viruses
At Windstone Farm, we are committed to growing exceptional dahlia tubers by combining loving care with cutting-edge plant science.
Our dedication ensures you’ll receive healthy, vibrant tubers to bring beauty and joy to your garden. While we’re not yet offering "Certified Virus-Free" dahlias, our rigorous testing and growing practices have achieved remarkable results. Over the past two growing seasons, our field-grown PREMIUM tubers have maintained exceptionally low virus infection rates:
Tobacco Streak Virus (TSV): Only 1% infected in both 2023 and 2024.
Dahlia Mosaic Viruses (DMVC/DMV): 3.3% (2023) and 12% (2024) infection rates.
Tomato spotted wilt virus (TSWV) 0% for both 2023 and 2024
Our system prioritizes clean, healthy stock to provide you with tubers that are “Virus Freer” and set the standard for quality.