This source reports 9 treatments. All are shown.
Protocol 1
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
No stated waiting before sowing. Then 63 days to germinate.
100% germination in 35–63 days.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around October 4, 2026 for a May 3 last frost.
- 1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 6 months from start to sowing. Then 3 days to germinate.
100% germination in 3 days.
Protocol 3
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around May 6, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on May 5, 2025.
- 1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
15 germinated in this phase.
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3 germinated in this phase.
- 3
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
70 germinated in this phase.
- 4
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
3 germinated in this phase.
- 5
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 6
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
85 germinated in this phase.
- 7
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 8
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
75 germinated in this phase.
Steps after step 7 run on after germination.
about 1.5 years from start to sowing. Then 70 days to germinate.
100% germination in 14–70 days.
Protocol 4
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around July 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 22, 2026.
- 1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
60 germinated in this phase.
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
50 germinated in this phase.
- 4
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
30 germinated in this phase.
Steps after step 2 run on after germination.
about 6 months from start to sowing. Then 77 days to germinate.
88% germination in 14–77 days.
Protocol 5
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around February 8, 2027 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
No stated waiting before sowing. Then 56 days to germinate.
86% germination in 14–56 days.
This source doesn't state how long.
Protocol 6
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around February 8, 2027 for a May 3 last frost.
- 1
Cold moist stratification
Temperature: 40°F 4°C
No stated waiting before sowing. Then 56 days to germinate.
86% germination in 21–56 days.
This source doesn't state how long.
Protocol 7
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around November 3, 2026 for a May 3 last frost.
- 1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
70 germinated in this phase.
- 3
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
9 germinated in this phase.
Steps after step 1 run on after germination.
about 3 months from start to sowing. Then 63 days to germinate.
86% germination in 14–63 days.
Protocol 8
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around September 29, 2026 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 28, 2025.
- 1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
11 germinated in this phase.
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
15 germinated in this phase.
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
25 germinated in this phase.
- 4
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
25 germinated in this phase.
- 5
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
12 germinated in this phase.
- 6
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 7
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
65 germinated in this phase.
- 8
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
20 germinated in this phase.
Steps after step 6 run on after germination.
about 18 months from start to sowing. Then 14 days to germinate.
75% germination in 14 days.
Protocol 9
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around June 19, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 18, 2026.
- 1
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
2 germinated in this phase.
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 3
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 4
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
Steps after step 3 run on after germination.
about 9 months from start to sowing. Germination time not stated; 21 days assumed.
44% germination.