Allium neapolitanum
Genus Allium
This source reports 5 treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1998Difficulty Low Rated by us, not by the source.
Start around August 20, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on August 19, 2026.
- 1
Dry storage
Duration: 180 days · Temperature: 70°F 21°C
- 2
Cold moist stratification
Temperature: 40°F 4°C
about 6 months from start to sowing. Then 49 days to germinate.
100% germination in 49 days.
This source doesn't state how long.
Protocol 2
DerivedN. C. Deno, 1998Difficulty Moderate Rated by us, not by the source.
Start around February 7, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on February 6, 2026.
- 1
Dry storage
Duration: 180 days · Temperature: 70°F 21°C
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 12 months from start to sowing. Then 63 days to germinate.
100% germination in 63 days.
Protocol 3
DerivedN. C. Deno, 1998Difficulty Moderate Rated by us, not by the source.
Start around January 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on January 16, 2026.
- 1
Dry storage
Duration: 180 days · Temperature: 70°F 21°C
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: light
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 12 months from start to sowing. Then 84 days to germinate.
100% germination in 56–84 days.
Protocol 4
DerivedN. C. Deno, 1998Difficulty Moderate Rated by us, not by the source.
Start around November 18, 2026 for a May 3 last frost. Too late for spring 2027 — that needed starting on November 17, 2025.
- 1
Dry storage
Duration: 365 days · Temperature: 70°F 21°C
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 3
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
Steps after step 2 run on after germination.
about 15 months from start to sowing. Then 49 days to germinate.
44% germination in 49 days.
Protocol 5
DerivedN. C. Deno, 1998Difficulty Moderate Rated by us, not by the source.
Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2025.
- 1
Dry storage
Duration: 365 days · Temperature: 70°F 21°C
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
1/10 germinated in this phase.
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 1.5 years from start to sowing. Then 21 days to germinate.
30% germination in 21 days.