Two sources report 4 treatments between them. All are shown.
Protocol 1
DerivedSER, INSR and RBG Kew, 2026Difficulty Low Rated by us, not by the source.
Start around March 15, 2027 for a May 3 last frost.
- 1
Sow and cover
Temperature: 70°F 21°C · Light: either · Medium: 1% agar
12 hours light, 12 dark.
No stated waiting before sowing. Germination time not stated; 21 days assumed.
100% germination.
Twice Deno's figure at the same temperature.
Protocol 2
DerivedSER, INSR and RBG Kew, 2026Difficulty Low Rated by us, not by the source.
Start around January 25, 2027 for a May 3 last frost.
- 1
Sow and cover
Duration: 35 days · Temperature: 59°F 15°C · Light: either · Medium: 1% agar
12 hours light, 12 dark.
about 5 weeks from start to sowing. Then 35 days to germinate.
95% germination in 35 days.
Protocol 3
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 and cover
Temperature: 70°F 21°C · Light: either
No stated waiting before sowing. Then 14 days to germinate.
40% germination in 14 days.
Deno gives 40-50%. Neither light nor GA-3 changed the result.
Protocol 4
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around February 1, 2027 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
Germinates in the cold, in 3-9 weeks.
No stated waiting before sowing. Then 63 days to germinate.
50% germination in 21–63 days.
This source doesn't state how long.