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Trillium grandiflorum

Large-flower Trillium · Great White Trillium · Large White Trillium

Family MelanthiaceaeGenus Trillium

A white flower of three broad pointed petals with wavy edges and yellow stamens, above a whorl of three veined leaves.
FlowerPaul JohnstonCC 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, WildflowerExtension Gardener Plant Toolbox
Habit
rhizomatous geophytePlants of the World Online
Height
1-3 ft30-90 cmExtension Gardener Plant Toolbox
Spread
0.8-1 ft25-30 cmExtension Gardener Plant Toolbox
Flower
Pink, WhiteExtension Gardener Plant Toolbox
Blooms
SpringExtension Gardener Plant Toolbox
Native range
Canada, lower 48 statesPLANTS Database
Hardiness zones
4-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Dappled Sunlight; Deep shade; Partial ShadeExtension Gardener Plant Toolbox
Soil
High Organic MatterExtension Gardener Plant Toolbox
Soil pH
Acid (<6.0), 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; PLANTS Database — USDA NRCS.

Worth knowing

Two sources report 4 treatments between them. All are shown.

Protocol 1

DerivedN. C. Deno, 1998

Difficulty Moderate Rated by us, not by the source.

Start around November 10, 2026 for a May 3 last frost.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 3 months from start to step 2. Germination happens during step 2, in 56 days.

80% germination in 56 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Trillium p. 65Public domain
Show the original text
Trillium (Liliaceae). T. grandiflorum was much studied (2nd Ed.) and found to require GA-3 for germination. A large sample was received which contained 26% dead seeds which started rotting in a few days in 70D. This large amount of rotting caused the remaining seeds to start germinating. This is interpreted as due to gibberellins being produced by the decay, because,seeds left in the rot germ. 44% in 8-15 w in 70D and 40-70(80% in 8th w) whereas none germ. if washed every few days: . ..
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Trillium p. 65. 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 Low Rated by us, not by the source.

Start around January 18, 2027 for a May 3 last frost.

  1. Gibberellic acid soak

  2. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 77 days to germinate.

74% germination in 49–77 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Trillium p. 223Public domain
Show the original text
Trillium (Llliaceae). Gibberelins are at least desirable if not requisite for both germination and the production of healthy seedlings. More work is necessary before an optimum procedure can be recommended. The GA-3 treatment was tried with fresh seeds of T. grandiflorum germ. 70 GA-3(74% in 7-11 w) and 70D(none). Although the cotyledons were starting to expand, the seedlings were placed at 40 at the end of the 12th w. They continued to show a little growth so that after 4 w at 40, they were placed at 60 whereupon they gradually opened their cotyledons over the next 3 m. It was thus possible to get the first leaf within 6 m of seed collection. More work is needed to define the optimum treatment. Earlier samples germ. 70(22%)-40-70-40- 70(24%)-40(3%) and 40-70(42%)-40(31%) without GA-3, but the cotyledons failed to develop suggesting that gibberelins are required for healthy seedlings.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Trillium p. 223. 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

Difficulty 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 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

    31 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; time not stated, 21 days assumed.

42% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Trillium p. 223Public domain
Show the original text
Trillium (Llliaceae). Gibberelins are at least desirable if not requisite for both germination and the production of healthy seedlings. More work is necessary before an optimum procedure can be recommended. The GA-3 treatment was tried with fresh seeds of T. grandiflorum germ. 70 GA-3(74% in 7-11 w) and 70D(none). Although the cotyledons were starting to expand, the seedlings were placed at 40 at the end of the 12th w. They continued to show a little growth so that after 4 w at 40, they were placed at 60 whereupon they gradually opened their cotyledons over the next 3 m. It was thus possible to get the first leaf within 6 m of seed collection. More work is needed to define the optimum treatment. Earlier samples germ. 70(22%)-40-70-40- 70(24%)-40(3%) and 40-70(42%)-40(31%) without GA-3, but the cotyledons failed to develop suggesting that gibberelins are required for healthy seedlings.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Trillium p. 223. 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 4

DerivedN. C. Deno, 1993

Difficulty 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. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    22 germinated in this phase.

  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

  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 5 run on after germination.

about 12 months from start to step 5. Germination happens during step 5; time not stated, 21 days assumed.

24% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Trillium p. 223Public domain
Show the original text
Trillium (Llliaceae). Gibberelins are at least desirable if not requisite for both germination and the production of healthy seedlings. More work is necessary before an optimum procedure can be recommended. The GA-3 treatment was tried with fresh seeds of T. grandiflorum germ. 70 GA-3(74% in 7-11 w) and 70D(none). Although the cotyledons were starting to expand, the seedlings were placed at 40 at the end of the 12th w. They continued to show a little growth so that after 4 w at 40, they were placed at 60 whereupon they gradually opened their cotyledons over the next 3 m. It was thus possible to get the first leaf within 6 m of seed collection. More work is needed to define the optimum treatment. Earlier samples germ. 70(22%)-40-70-40- 70(24%)-40(3%) and 40-70(42%)-40(31%) without GA-3, but the cotyledons failed to develop suggesting that gibberelins are required for healthy seedlings.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Trillium p. 223. 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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