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Agastache nepetoides

Catnip Giant Hyssop · Yellow Giant Hyssop

Family LamiaceaeGenus Agastache

A dense green flower spike studded with small pale tubular flowers and protruding stamens, above toothed heart-shaped leaves
FlowerFritzflohrreynoldsCC BY-SA 3.0

About the plant

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

Habit
perennialPlants of the World Online
Habit
Perennial, Forb/herb, SubshrubPLANTS Database
Flower
WhiteRead from the photograph on this page
Native range
Canada, lower 48 statesPLANTS 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; Read from the photograph on this page — Deno's Garden.

Worth knowing

  • Yellow giant hyssop flowers in late summer and is very attractive to bees. It is listed as endangered in Connecticut and Georgia, and as threatened in New York, Vermont and Wisconsin. Wikipedia: Agastache nepetoides

Two sources report 6 treatments between them. All are shown.

Protocol 1

DerivedN. C. Deno, 1996

Difficulty Moderate Rated by us, not by the source.

Start around March 22, 2027 for a May 3 last frost.

  1. Sow and cover

    Temperature: 70°F 21°C Light: light

No stated waiting before sowing. Then 14 days to germinate.

57% germination in 14 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Agastache p. 16Public domain
Show the original text
Agastache (Lamiaceae). Light was required for the two species studied. A. nepetoides germ. 70L(57% in 2nd w) (2nd Ed.) and 70D(none). This pattern and the rate were unchanged after 2 y of DS, but the germination declined to 28% (still in 2nd w), and seeds DS 3 y were all dead.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Agastache p. 16. 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 September 24, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 23, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Gibberellic acid soak

  3. Sow and cover

    Temperature: 70°F 21°C

about 6 months from start to sowing. Then 14 days to germinate.

98% germination in 14 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Agastache p. 89Public domain
Show the original text
Agastache (Lamiaceae). Results were complex with the stimulation of germination by light and GA-3 being eliminated by 3 m at 40 in A. nepetoides germ. 70L(57% in 5-15 d), 70D GA-3(95% in 5-13 d), 70D(none), 40-70L(92% in 4-8 d), and 40-70D(n6ne) using fresh seed. Outdoor treatment germ. 4% in April. Seeds DS 6 m at 70 germ. 70L(22% in 2nd w), 70 GA-3(98% in 2nd w), 70D(none), and 40(none).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Agastache p. 89. 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 Low Rated by us, not by the source.

Start around March 23, 2027 for a May 3 last frost.

  1. Gibberellic acid soak

  2. Sow and cover

    Temperature: 70°F 21°C Light: dark

No stated waiting before sowing. Then 13 days to germinate.

95% germination in 5–13 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Agastache p. 89Public domain
Show the original text
Agastache (Lamiaceae). Results were complex with the stimulation of germination by light and GA-3 being eliminated by 3 m at 40 in A. nepetoides germ. 70L(57% in 5-15 d), 70D GA-3(95% in 5-13 d), 70D(none), 40-70L(92% in 4-8 d), and 40-70D(n6ne) using fresh seed. Outdoor treatment germ. 4% in April. Seeds DS 6 m at 70 germ. 70L(22% in 2nd w), 70 GA-3(98% in 2nd w), 70D(none), and 40(none).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Agastache p. 89. 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 Moderate Rated by us, not by the source.

Start around December 28, 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 Light: light

about 3 months from start to step 2. Germination happens during step 2, in 8 days.

92% germination in 4–8 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Agastache p. 89Public domain
Show the original text
Agastache (Lamiaceae). Results were complex with the stimulation of germination by light and GA-3 being eliminated by 3 m at 40 in A. nepetoides germ. 70L(57% in 5-15 d), 70D GA-3(95% in 5-13 d), 70D(none), 40-70L(92% in 4-8 d), and 40-70D(n6ne) using fresh seed. Outdoor treatment germ. 4% in April. Seeds DS 6 m at 70 germ. 70L(22% in 2nd w), 70 GA-3(98% in 2nd w), 70D(none), and 40(none).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Agastache p. 89. 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 5

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around September 24, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 23, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: light

about 6 months from start to sowing. Then 14 days to germinate.

22% germination in 14 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Agastache p. 89Public domain
Show the original text
Agastache (Lamiaceae). Results were complex with the stimulation of germination by light and GA-3 being eliminated by 3 m at 40 in A. nepetoides germ. 70L(57% in 5-15 d), 70D GA-3(95% in 5-13 d), 70D(none), 40-70L(92% in 4-8 d), and 40-70D(n6ne) using fresh seed. Outdoor treatment germ. 4% in April. Seeds DS 6 m at 70 germ. 70L(22% in 2nd w), 70 GA-3(98% in 2nd w), 70D(none), and 40(none).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Agastache p. 89. 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 6

DerivedN. C. Deno, 1993

Difficulty Very high Rated by us, not by the source.

  1. Sow outdoors and leave it

    Up in April.

No stated waiting before sowing.

4% germination.

This source doesn't state how long step 1 lasts.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Agastache p. 89Public domain
Show the original text
Agastache (Lamiaceae). Results were complex with the stimulation of germination by light and GA-3 being eliminated by 3 m at 40 in A. nepetoides germ. 70L(57% in 5-15 d), 70D GA-3(95% in 5-13 d), 70D(none), 40-70L(92% in 4-8 d), and 40-70D(n6ne) using fresh seed. Outdoor treatment germ. 4% in April. Seeds DS 6 m at 70 germ. 70L(22% in 2nd w), 70 GA-3(98% in 2nd w), 70D(none), and 40(none).
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Agastache p. 89. 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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