This source reports 5 treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1998Difficulty Low Rated by us, not by the source.
Start around October 26, 2026 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
No stated waiting before sowing. Then 161 days to germinate.
100% germination in 91–161 days.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1998Difficulty Moderate Rated by us, not by the source.
Start around July 30, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 29, 2026.
- 1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 6 months from start to sowing. Then 70 days to germinate.
92% germination in 42–70 days.
Protocol 3
DerivedN. C. Deno, 1998Difficulty Low Rated by us, not by the source.
Start around March 15, 2027 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
No stated waiting before sowing. Germination time not stated; 21 days assumed.
79% germination.
This source doesn't state how long.
Protocol 4
DerivedN. C. Deno, 1998Difficulty Moderate Rated by us, not by the source.
Start around July 30, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 29, 2026.
- 1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 6 months from start to sowing. Then 70 days to germinate.
44% germination in 49–70 days.
Protocol 5
DerivedN. C. Deno, 1998Difficulty High Rated by us, not by the source.
Start around September 24, 2026 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 23, 2025.
- 1
Dry storage
Duration: 365 days · Temperature: 70°F 21°C
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 1.5 years from start to sowing. Then 14 days to germinate.
20% germination in 14 days.