Iris graeberiana
Genus Iris
This source reports 7 treatments. All are shown.
Protocol 1
DerivedN. C. Deno, 1993Difficulty Moderate Rated by us, not by the source.
Start around April 24, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on April 23, 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
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 9 months from start to sowing. Then 77 days to germinate.
91% germination in 42–77 days.
Protocol 2
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around December 15, 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
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2/12 germinated in this phase.
Steps after step 1 run on after germination.
about 3 months from start to sowing. Germination time not stated; 21 days assumed.
42% germination.
Protocol 3
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around March 21, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 20, 2026.
- 1
Dry storage
Duration: 180 days · Temperature: 40°F 4°C
- 2
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 3
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 4
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
1/14 germinated in this phase.
- 5
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2/14 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
- 8
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 9
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2/14 germinated in this phase.
- 10
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 11
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 12
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 13
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2/14 germinated in this phase.
Steps after step 3 run on after germination.
about 12 months from start to sowing. Germination time not stated; 21 days assumed.
29% germination.
Protocol 4
DerivedN. C. Deno, 1993Difficulty High Rated by us, not by the source.
Start around December 21, 2026 for a May 3 last frost. Too late for spring 2027 — that needed starting on December 20, 2025.
- 1
Dry storage
Duration: 180 days · Temperature: 40°F 4°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
2/14 germinated in this phase.
- 4
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 5
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 6
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2/14 germinated in this phase.
- 7
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
1/14 germinated in this phase.
- 8
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 9
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
Steps after step 4 run on after germination.
about 15 months from start to sowing. Germination time not stated; 21 days assumed.
21% germination.
Protocol 5
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
Dry storage
Duration: 180 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
1/20 germinated in this phase.
- 4
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 5
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 6
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
2/20 germinated in this phase.
- 7
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 8
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
Steps after step 2 run on after germination.
about 9 months from start to sowing. Germination time not stated; 21 days assumed.
15% germination.
Protocol 6
DerivedN. C. Deno, 1993Difficulty High 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
No stated waiting before sowing. Germination time not stated; 21 days assumed.
10% germination.
Protocol 7
DerivedN. C. Deno, 1993Difficulty Very high Rated by us, not by the source.
Start around September 22, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 21, 2025.
- 1
Warm moist stratification
Duration: 90 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
- 4
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
- 5
Warm moist stratification
Duration: 90 days · Temperature: 70°F 21°C
- 6
Cold moist stratification
Duration: 90 days · Temperature: 40°F 4°C
about 18 months from start to sowing. Germination time not stated; 21 days assumed.
5% germination.
How each step is done, in Deno’s words, and what Verified and Derived mean.