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Alisma plantago-aquatica

Genus Alisma

Tall airy flower stems branching in whorled tiers above broad spear-shaped basal leaves, at a pond margin
The whole plantChristian FischerCC 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, Water PlantExtension Gardener Plant Toolbox
Height
2-3 ft60-90 cmExtension Gardener Plant Toolbox
Spread
1-2 ft30-60 cmExtension Gardener Plant Toolbox
Flower
Pink, Purple/Lavender, WhiteExtension Gardener Plant Toolbox
Blooms
Spring, SummerExtension Gardener Plant Toolbox
Hardiness zones
5-9Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Clay, Loam (Silt), SandExtension Gardener Plant Toolbox
Soil pH
Acid (<6.0), Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Frequent Standing WaterExtension Gardener Plant Toolbox

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

Source: Extension Gardener Plant Toolbox — NC State Extension.

This source reports three treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1998

Difficulty Moderate Rated by us, not by the source.

Start around January 9, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on January 8, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: light

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: dark

about 15 months from start to sowing. Then 2 days to germinate.

100% germination in 2 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Alisma p. 12Public domain
Show the original text
Alisma (Aiismaceae). A. plantago-aquatica exhibited the remarkable and unusual phenomena of a delayed light effect as discussed in the Introduction. Seeds DS 6 m germ. 70L-40-70D(100% on 2nd d), 40-70L-40-70D(70% on 3rd d), and none in 70D-40-70D. An initial month of OS had little effect. Seeds DS 1 y were dead.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Alisma p. 12. 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, 1998

Difficulty Moderate Rated by us, not by the source.

Start around October 10, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on October 9, 2025.

  1. Dry storage

    Duration: 180 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 Light: light

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  5. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C Light: dark

about 18 months from start to sowing. Then 3 days to germinate.

70% germination in 3 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Alisma p. 12Public domain
Show the original text
Alisma (Aiismaceae). A. plantago-aquatica exhibited the remarkable and unusual phenomena of a delayed light effect as discussed in the Introduction. Seeds DS 6 m germ. 70L-40-70D(100% on 2nd d), 40-70L-40-70D(70% on 3rd d), and none in 70D-40-70D. An initial month of OS had little effect. Seeds DS 1 y were dead.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Alisma p. 12. 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, 1998

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: dark

about 6 months from start to sowing.

0% germination.

Nothing germinated at 70.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Alisma p. 12Public domain
Show the original text
Alisma (Aiismaceae). A. plantago-aquatica exhibited the remarkable and unusual phenomena of a delayed light effect as discussed in the Introduction. Seeds DS 6 m germ. 70L-40-70D(100% on 2nd d), 40-70L-40-70D(70% on 3rd d), and none in 70D-40-70D. An initial month of OS had little effect. Seeds DS 1 y were dead.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Alisma p. 12. 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.

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