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 21, 2027 for a May 3 last frost.
- 1
Sow and cover
Temperature: 70°F 21°C · Light: dark
No stated waiting before sowing. Then 15 days to germinate.
100% germination in 5–15 days.
Fresh seed or six months' dry storage at 70 or 40 -- it made no difference.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around March 22, 2027 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
- 2
Warm moist stratification
Temperature: 70°F 21°C
100% after the move, in 2 days to 2 weeks.
No stated waiting before sowing. Then 14 days to germinate.
100% germination in 2–14 days.
This source doesn't state how long.