Difficulty ModerateRated by us, not by the source.
Start around July 5, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 4, 2025.
1
Dry storage
Duration: 180 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
4
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
5
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
6
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
about 1.5 years from start to sowing. Then 10 days to germinate.
90% germination in 6–10 days.
Protocol 2
DerivedN. C. Deno, 1996
Difficulty ModerateRated by us, not by the source.
Start around April 4, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on April 3, 2025.
1
Dry storage
Duration: 180 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
5
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
6
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
7
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 2 years from start to sowing. Then 12 days to germinate.
71% germination in 4–12 days.
Protocol 3
DerivedN. C. Deno, 1996
Difficulty HighRated by us, not by the source.
Start around June 26, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 25, 2026.
1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: light
6 germinated in this phase.
2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: light
about 9 months from start to sowing. Then 14 days to germinate.
60% germination in 14 days.
Protocol 4
DerivedN. C. Deno, 1996
Difficulty ModerateRated by us, not by the source.
Sow around September 2027 — a date the source gives, not one counted back from a May 3 last frost. Too late for spring 2027 — that needed starting on September 2026.
1
Sow outdoors and leave it
Sown outdoors in September; up in April.
No stated waiting before sowing. Then 210 days to germinate.
58% germination in 210 days.
This source doesn't state how long.
Protocol 5
DerivedN. C. Deno, 1996
Difficulty ModerateRated by us, not by the source.
Sow around March 2027 — a date the source gives, not one counted back from a May 3 last frost.
1
Dry storage
Duration: 180 days · Temperature: 70°F 21°C
2
Sow outdoors and leave it
Sown outdoors in March; up in March and April.
about 6 months from start to sowing. Germination time not stated; 21 days assumed.
43% germination.
This source doesn't state how long.
Protocol 6
DerivedN. C. Deno, 1996
Difficulty HighRated by us, not by the source.
Start around June 12, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 11, 2026.
1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
6 germinated in this phase.
2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
about 9 months from start to sowing. Then 28 days to germinate.