Deno’s Garden

Helleborus niger

Genus Helleborus

This source reports two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around August 6, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on August 5, 2026.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 6 months from start to sowing. Then 63 days to germinate.

93% germination in 63 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Helleborus p. 151Public domain
Show the original text
Helleborus (Ranunculaceae). - H. niger germ. 70-40(93% in 9th w) and 40-70-40(19%)-70(25% in 2 d)- 40(44%). The 25% germination at 70 may have begun at 40.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Helleborus p. 151. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 2

DerivedN. C. Deno, 1993

Difficulty 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. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    19 germinated in this phase.

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    25 germinated in this phase.

  5. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 15 months from start to sowing. Germination time not stated; 21 days assumed.

44% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Helleborus p. 151Public domain
Show the original text
Helleborus (Ranunculaceae). - H. niger germ. 70-40(93% in 9th w) and 40-70-40(19%)-70(25% in 2 d)- 40(44%). The 25% germination at 70 may have begun at 40.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Helleborus p. 151. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.