Viola sororia, commonly known as common blue violet or butterfly violet, is a native herbaceous perennial found throughout eastern and central North America, and is the state flower of Illinois, Rhode Island, New Jersey, and Wisconsin. This species exhibits double dormancy, requiring both warm and cold stratification periods to break seed dormancy. Seeds typically germinate 4-12 weeks after the warming period following cold stratification.
Before sowing
Warm stratify at room temperature (approximately 70°F) for 4 weeks, then cold stratify in refrigerator for 6 weeks at 40°F (4°C). Keep soil moist throughout the stratification process.
Sowing
What to expect
Tips
Sow seeds 1/16 inch deep and tamp the soil firmly. Mulch the seed bed lightly after sowing. Use well-drained seed-starting mix with added coarse sand or limestone chips. Keep soil consistently moist throughout germination. Germination is erratic and can span many weeks; do not discard seeds if mold appears, as they may still germinate. Seeds are highly viable only about one year when stored dry at room temperature; store in refrigerator but keep moist. Sow in late fall/winter outdoors for natural cold stratification, or use the warm-then-cold method indoors.
Sources: Sheffield Seeds, Ferri Seeds, Brian's Native Plants, Prairie Moon Nursery, New England Wildflower Society, Project MUSE, research literature
