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Verbena hastata

American Blue Vervain · American Vervain · Blue Vervain · Swamp Verbena

Family VerbenaceaeGenus Verbena

Slender green spikes carrying rings of small violet flowers part way up, above long toothed leaves.
FlowerCody HoughCC 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
biennial or perennialPlants of the World Online
Height
2-5 ft0.6-1.5 mExtension Gardener Plant Toolbox
Spread
1-2.5 ft30-75 cmExtension Gardener Plant Toolbox
Flower
Blue, Purple/LavenderExtension Gardener Plant Toolbox
Blooms
SummerExtension Gardener Plant Toolbox
Native range
Canada, lower 48 statesPLANTS Database
Hardiness zones
3-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Clay, Loam (Silt), SandExtension Gardener Plant Toolbox
Moisture
Moist, Occasionally WetExtension 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

This source reports two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around July 5, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 4, 2026.

  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

about 9 months from start to step 3. Germination happens during step 3, in 5 days.

100% germination in 3–5 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Verbena p. 227Public domain
Show the original text
Verbena (Verbenaceae). V. hastata germ. 40-70L(100% in 3-5 d), 70D GA- 3(54% in 5-25 d, mainly in 5-10 d) and none in 700 or 70L using either seeds collected in November or seeds collected in September and DS 6 m or 12 m at 70. Fresh seeds collected in September gave lower germination in 40-70L. Other treatments failed. The rate of destruction of inhibitor was studied. Seeds DS 12 m at 70 were held at 40 for 4 w, 8 w, and 12 w before shifting to 70L. Germinations were 2%, 100%, and 100% showing that 6-8 w were required.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Verbena p. 227. 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 September 13, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 12, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Gibberellic acid soak

  3. Sow and cover

    Temperature: 70°F 21°C Light: dark

about 6 months from start to sowing. Then 25 days to germinate.

54% germination in 5–25 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Verbena p. 227Public domain
Show the original text
Verbena (Verbenaceae). V. hastata germ. 40-70L(100% in 3-5 d), 70D GA- 3(54% in 5-25 d, mainly in 5-10 d) and none in 700 or 70L using either seeds collected in November or seeds collected in September and DS 6 m or 12 m at 70. Fresh seeds collected in September gave lower germination in 40-70L. Other treatments failed. The rate of destruction of inhibitor was studied. Seeds DS 12 m at 70 were held at 40 for 4 w, 8 w, and 12 w before shifting to 70L. Germinations were 2%, 100%, and 100% showing that 6-8 w were required.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Verbena p. 227. 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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