Phlox speciosa
Genus Phlox
Two sources report 4 treatments between them. All are shown.
Protocol 1
DerivedN. C. Deno, 1996Difficulty Moderate 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
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 6 months from start to sowing. Then 49 days to germinate.
50% germination in 21–49 days.
Protocol 2
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
about 6 months from start to sowing. Then 21 days to germinate.
40% germination in 21 days.
Protocol 3
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around July 16, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 15, 2026.
- 1
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
3/18 germinated in this phase.
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
about 6 months from start to sowing. Then 84 days to germinate.
28% germination in 7–84 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
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 2
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 6 months from start to sowing. Then 77 days to germinate.
50% germination in 21–77 days.