This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around January 8, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on January 7, 2026.
- 1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
7 germinated in this phase.
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
7 germinated in this phase.
- 3
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
7 germinated in this phase.
- 4
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
27 germinated in this phase.
- 5
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 15 months from start to sowing. Then 3 days to germinate.
33% germination in 2–3 days.
Protocol 2
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around September 28, 2026 for a May 3 last frost.
- 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. Then 9 days to germinate.
17% germination in 6–9 days.