This source reports three treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around March 24, 2027 for a May 3 last frost.
- 1
Sow and cover
Temperature: 70°F 21°C · Light: either
No stated waiting before sowing. Then 12 days to germinate.
60% germination in 2–12 days.
60% in under a fortnight. The straightforward route.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around February 22, 2027 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
46%, over 2-6 weeks.
- 2
Warm moist stratification
Temperature: 70°F 21°C
Nothing further.
No stated waiting before sowing. Then 42 days to germinate.
46% germination in 14–42 days.
46% in the cold itself, and nothing at all after the move to 70.
This source doesn't state how long.
Protocol 3
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around March 15, 2027 for a May 3 last frost.
- 1
Sow outdoors and leave it
Up in March.
No stated waiting before sowing. Germination time not stated; 21 days assumed.
40% germination.
40%, up in March.
This source doesn't state how long.