Astrantia involucrata
This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1998Difficulty High
Start around January 31, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on January 30, 2026.
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C Light: dark
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C Light: either
27 germinated in this phase.
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C Light: dark
7 germinated in this phase.
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C Light: either
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C Light: either
8 germinated in this phase.
Steps after step 4 run on after germination.
about 12 months from start to sowing. Then 70 days to germinate.
50% germination in 56–70 days.
Protocol 2
DerivedN. C. Deno, 1998Difficulty High
Start around October 19, 2026 for a May 3 last frost. Too late for spring 2027 — that needed starting on October 18, 2025.
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C Light: either
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C Light: either
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C Light: either
30 germinated in this phase.
Warm moist stratification
Duration: 90 daysTemperature: 70°F 21°C Light: either
25 germinated in this phase.
Cold moist stratification
Duration: 90 daysTemperature: 40°F 4°C Light: either
about 15 months from start to sowing. Then 84 days to germinate.
45% germination in 84 days.