This source reports 4 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.
27% germination.
The best of four, by a point, and the least work.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around December 29, 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
26%, in 4-7 days.
about 3 months from start to sowing. Then 7 days to germinate.
26% germination in 4–7 days.
A cold period beats sowing warm, and is quicker after the move.
This source doesn't state how long.
Protocol 3
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around March 27, 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 9 days to germinate.
22% germination in 8–9 days.
22% in light against 12% in dark.
Protocol 4
DerivedN. C. Deno, 1993Difficulty High 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.
12% germination in 12–15 days.
Half the lit result, and slower.