This source reports three treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1993
Difficulty HighRated by us, not by the source.
Start around February 4, 2027 for a May 3 last frost.
1
Sow and cover
Temperature: 70°F 21°C
No stated waiting before sowing. Then 60 days to germinate.
20% germination in 30–60 days.
The seedlings do not develop properly. The cold period is worth the wait.
Protocol 2
DerivedN. C. Deno, 1993
Difficulty LowRated by us, not by the source.
Start around December 29, 2026 for a May 3 last frost.
1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2
Sow and cover
Temperature: 70°F 21°C
about 3 months from start to sowing. Then 7 days to germinate.
Germinates in 1–7 days.
Deno's percentage is printed "109%" and cannot be read. The three months at 40 can be moist or dry: the seeds are large enough to carry their own moisture.