This source reports 4 treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around March 22, 2027 for a May 3 last frost.
- 1
Sow on the surface — do not cover
Temperature: 70°F 21°C · Light: light
No stated waiting before sowing. Then 14 days to germinate.
59% germination in 3–14 days.
The best of four, and outdoors nearly matches it.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Low 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.
58% germination.
58% for no work at all -- a point behind the best bench result.
This source doesn't state how long.
Protocol 3
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around March 22, 2027 for a May 3 last frost.
- 1
Sow and cover
Temperature: 70°F 21°C · Light: dark
No stated waiting before sowing. Then 14 days to germinate.
43% germination in 3–14 days.
Light is worth sixteen points here.
Protocol 4
DerivedN. C. Deno, 1993- 1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
Deno gives no length for this period; three months is his standard cycle.
- 2
Warm moist stratification
Temperature: 70°F 21°C
about 3 months from start to sowing.
0% germination.
Nothing. A cold period does not merely slow this one down, it stops it.
This source doesn't state how long.