Mendel’s Gardens

Veratrum californicum

California False Hellebore · Corn Lily

Family MelanthiaceaeGenus Veratrum

About the plant

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

Safety

Toxicity
Poisonous to sheep. All parts. Cylcopamine.

The plant

Habit
Perennial, Forb/herb
Height
6 ft
Flower
White
Blooms
Mid Spring
Native range
Native to the lower 48 states

Growing conditions

Sun
Shade tolerance: Low
Moisture
Moisture use: High

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

Sources: PLANTS Database — USDA NRCS; Plants Poisonous to Livestock — Cornell University Department of Animal Science.

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 sowing. Then 70 days to germinate.

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.

This source doesn't state how long.

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 sowing. Then 35 days to germinate.

67% germination in 35 days.

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

This source doesn't state how long.

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 sowing.

0% germination.

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

This source doesn't state how long.

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.