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Helleborus argutifolius

Corsican Hellebore

Family RanunculaceaeGenus Helleborus

A leafy stem crowned with nodding pale green cup-shaped flowers above spiny-edged three-part leaves on pine needles
The whole plantPicture taken by User:TigerenteCC BY-SA 3.0

About the plant

What it is and where it grows — not part of any germination protocol.

The plant

Habit
Herbaceous Perennial, PerennialExtension Gardener Plant Toolbox
Habit
biennial or subshrubPlants of the World Online
Height
1.5-2 ft45-60 cmExtension Gardener Plant Toolbox
Spread
1.5-2 ft45-60 cmExtension Gardener Plant Toolbox
Flower
Cream/Tan, GreenExtension Gardener Plant Toolbox
Blooms
Spring, WinterExtension Gardener Plant Toolbox
Native range
Corse, SardegnaGBIF Backbone Taxonomy
Hardiness zones
6-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Dappled Sunlight; Deep shade; Partial ShadeExtension Gardener Plant Toolbox
Soil
High Organic Matter, SandExtension Gardener Plant Toolbox
Soil pH
Alkaline (>8.0), Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, MoistExtension Gardener Plant Toolbox

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Extension Gardener Plant Toolbox — NC State Extension; Plants of the World Online — Royal Botanic Gardens, Kew; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

  • Argutifolius means "with sharp-toothed leaves", for the spiny leaflets of the Corsican hellebore, which grows wild only on Corsica and Sardinia. Wikipedia: Helleborus argutifolius

Two sources report three treatments between them. All are shown.

Protocol 1

DerivedN. C. Deno, 1996

Difficulty High Rated by us, not by the source.

Start around October 21, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on October 20, 2026.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    21 germinated in this phase.

  5. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  6. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    3 germinated in this phase.

Steps after step 2 run on after germination.

about 3 months from start to step 2. Germination happens during step 2, in 77 days.

57% germination in 49–77 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Helleborus p. 48Public domain
Show the original text
Helleborus (Ranuncufaceae). The data for H. argutifolius is now complete. It germ. 70-40(57% in 7-11 w)-70-40(21% on 2nd d)-70-40(3%) and none in 40-70 or 70 GA-3.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Helleborus p. 48. 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, 1996

  1. Cold moist stratification

    Temperature: 40°F 4°C

Germination happens during step 1.

0% germination.

Nothing germinated at 40.

This source doesn't state how long step 1 lasts.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Helleborus p. 48Public domain
Show the original text
Helleborus (Ranuncufaceae). The data for H. argutifolius is now complete. It germ. 70-40(57% in 7-11 w)-70-40(21% on 2nd d)-70-40(3%) and none in 40-70 or 70 GA-3.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Helleborus p. 48. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list.

Protocol 3

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around October 21, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on October 20, 2026.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

about 3 months from start to step 2. Germination happens during step 2, in 77 days.

57% germination in 49–77 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. argutifolius germ. 70-40(57% in 7-11 w). Treatment with GA-3 at 70 not.only failed to stimulate germination but led to rapid rotting of the seeds. A prior 3m at 40 also led to complete rotting of the seeds.
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.

How each step is done, in Deno’s words, and what Verified and Derived mean.

Germination trials

Readers’ own records of sowing this species, published after review. Share your trial · All trials

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