This source reports three treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around December 15, 2026 for a May 3 last frost.
- 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 · Light: dark
about 3 months from start to sowing. Germination time not stated; 21 days assumed.
33% germination.
One seed of three -- but it was three seeds. Deno's samples here are tiny.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around March 30, 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 6 days to germinate.
25% germination in 5–6 days.
Three seeds of twelve. Deno puts the light effect no more strongly than "may be prompted".
Protocol 3
DerivedN. C. Deno, 1993- 1
Sow and cover
Temperature: 70°F 21°C · Light: dark
No stated waiting before sowing.
0% germination.
Nothing in the dark without a cold period first.