Erythronium americanum
This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty High
Start around July 16, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 15, 2026.
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C
5/12 germinated in this phase.
Steps after step 2 run on after germination.
about 6 months from start to sowing. Then 84 days to germinate.
58% germination in 70–84 days.
Protocol 2
DerivedN. C. Deno, 1993Difficulty High
Start around March 7, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 6, 2026.
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C
3/19 germinated in this phase.
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C
about 12 months from start to sowing. Then 35 days to germinate.
42% germination in 35 days.