This source reports two treatments. Both are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around March 30, 2027 for a May 3 last frost.
- 1
Sow and cover
Temperature: 70°F 21°C · Light: dark
No stated waiting before sowing. Then 6 days to germinate.
100% germination in 2–6 days.
Every seed inside a week, buried. Nothing else needed.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Moderate 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
60% -- it germinates in the cold.
- 2
Warm moist stratification
Temperature: 70°F 21°C
A further 40%.
No stated waiting before sowing. Germination time not stated; 21 days assumed.
60% germination.
60% in the cold and 40% more after the move -- the whole packet, the slow way round.
This source doesn't state how long.