Dodecatheon amethystinum
Genus Dodecatheon
This source reports three treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around July 6, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 5, 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
about 9 months from start to sowing. Then 4 days to germinate.
34% germination in 4 days.
Protocol 2
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around June 28, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 27, 2026.
- 1
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
1 germinated in this phase.
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 4
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 9 months from start to sowing. Then 12 days to germinate.
33% germination in 5–12 days.
Protocol 3
DerivedN. C. Deno, 1993Difficulty Very high Rated by us, not by the source.
Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.
- 1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 6 months from start to sowing. Germination time not stated; 21 days assumed.
6% germination.