Campanula americana
Genus Campanula
This source reports 4 treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Low Rated by us, not by the source.
Start around September 30, 2026 for a May 3 last frost.
- 1
Dry storage
Duration: 180 days · Temperature: 70°F 21°C
- 2
Sow and cover
Temperature: 70°F 21°C · Light: light
about 6 months from start to sowing. Then 7 days to germinate.
90% germination in 3–7 days.
Protocol 2
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around October 3, 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 · Light: light
about 6 months from start to sowing. Then 4 days to germinate.
90% germination in 2–4 days.
Protocol 3
DerivedN. C. Deno, 1993Difficulty 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, 2026.
- 1
Dry storage
Duration: 180 days · Temperature: 70°F 21°C
- 2
Sow and cover
Temperature: 70°F 21°C · Light: dark
about 6 months from start to sowing. Germination time not stated; 21 days assumed.
60% germination.
Protocol 4
DerivedN. C. Deno, 1993Difficulty 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, 2026.
- 1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C · Light: dark
about 6 months from start to sowing. Germination time not stated; 21 days assumed.
40% germination.