Helleborus argutifolius
Genus Helleborus
Two sources report three treatments between them. All are shown.
Protocol 1
DerivedN. C. Deno, 1996- 1
Cold moist stratification
Temperature: 40°F 4°C
No stated waiting before sowing.
0% germination.
Nothing germinated at 40.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1996Difficulty High Rated by us, not by the source.
Start around July 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 22, 2026.
- 1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 3
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 4
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
21 germinated in this phase.
- 5
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 6
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3 germinated in this phase.
Steps after step 2 run on after germination.
about 6 months from start to sowing. Then 77 days to germinate.
57% germination in 49–77 days.
Protocol 3
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around July 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 22, 2026.
- 1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 6 months from start to sowing. Then 77 days to germinate.
57% germination in 49–77 days.