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Veratrum californicum

California Corn Lily · California False Hellebore · California Veratrum · Corn Lily

Family MelanthiaceaeGenus Veratrum

Clumps of broad pleated leaves standing in a damp meadow
The whole plantJerryFriedmanCC BY-SA 3.0

About the plant

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

Safety

Toxicity
Poisonous to sheep. All parts. Cylcopamine.Plants Poisonous to Livestock

The plant

Habit
perennial or rhizomatous geophytePlants of the World Online
Habit
Perennial, Forb/herbPLANTS Database
Height
6 ft1.8 mPLANTS Database
Flower
WhitePLANTS Database
Blooms
Mid SpringPLANTS Database
Native range
Arizona, California, Colorado, Idaho, Mexico Northeast, Mexico Northwest and elsewhereGBIF Backbone Taxonomy

Growing conditions

Sun
Shade tolerance: LowPLANTS Database
Soil
Adapted to medium, fine textured soilsPLANTS Database
Soil pH
5.5-7.5PLANTS Database
Moisture
Moisture use: HighPLANTS Database
Watering
Drought tolerance: LowPLANTS Database

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

Sources: Plants of the World Online — Royal Botanic Gardens, Kew; PLANTS Database — USDA NRCS; GBIF Backbone Taxonomy — Global Biodiversity Information Facility; Plants Poisonous to Livestock — Cornell University Department of Animal Science.

Worth knowing

  • Extremely poisonous. It contains cyclopamine and related compounds that cause birth defects, including cyclopia, in sheep, horses and other grazing animals. Wikipedia: Veratrum californicum

This source reports three treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around July 30, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 29, 2026.

  1. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    Deno gives no length for this period; three months is his standard cycle.

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    Deno gives no length for this period; three months is his standard cycle.

  3. Warm moist stratification

    Temperature: 70°F 21°C

about 6 months from start to step 3. Germination happens during step 3, in 70 days.

75% germination in 7–70 days.

Three seeds of four. A warm period before the cold is what makes the difference: cold first gives nothing.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, VeratrumPublic domain
Show the original text
Veratrum (Liliaceae). V. calif ornicum , germ. 40-70 GA-3(2/3 in 5th w), 40-70(none), and 70-40-70(3/4 in 1-10 w).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Veratrum. 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 Moderate Rated by us, not by the source.

Start around December 1, 2026 for a May 3 last frost.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    Deno gives no length for this period; three months is his standard cycle.

  2. Gibberellic acid soak

  3. Warm moist stratification

    Temperature: 70°F 21°C

about 3 months from start to step 3. Germination happens during step 3, in 35 days.

67% germination in 35 days.

Two seeds of three. GA-3 rescues the cold-first route, which gives nothing without it.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, VeratrumPublic domain
Show the original text
Veratrum (Liliaceae). V. calif ornicum , germ. 40-70 GA-3(2/3 in 5th w), 40-70(none), and 70-40-70(3/4 in 1-10 w).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Veratrum. 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 3

DerivedN. C. Deno, 1993

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    Deno gives no length for this period; three months is his standard cycle.

  2. Warm moist stratification

    Temperature: 70°F 21°C

    Nothing.

about 3 months from start to step 2. Germination happens during step 2.

0% germination.

Nothing at all. The same treatment with GA-3 gave two seeds of three.

This source doesn't state how long step 2 lasts.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, VeratrumPublic domain
Show the original text
Veratrum (Liliaceae). V. calif ornicum , germ. 40-70 GA-3(2/3 in 5th w), 40-70(none), and 70-40-70(3/4 in 1-10 w).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Veratrum. Quoted exactly. Every value on this card comes from this record; 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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