This source reports three treatments. All are shown.
Protocol 1
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
No stated waiting before sowing. Germination time not stated; 21 days assumed.
20% germination.
Twice what the fridge gives, and the only sensible route.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around February 15, 2027 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
No stated waiting before sowing. Then 49 days to germinate.
10% germination in 49 days.
10% in the seventh week. Warmth alone gives nothing at all.
This source doesn't state how long.
Protocol 3
DerivedN. C. Deno, 1993- 1
Sow and cover
Temperature: 70°F 21°C · Light: either
No stated waiting before sowing.
0% germination.
Nothing, light or dark. This one will not start warm.