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Agastache foeniculum

Blue Giant Hyssop · Lavender Hyssop · Anise Hyssop

Family LamiaceaeGenus Agastache

A dense upright spike with small violet two-lipped flowers opening around a green bracted column
FlowerWayneRayPublic domain

About the plant

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

The plant

Habit
Herbaceous PerennialExtension Gardener Plant Toolbox
Habit
perennialPlants of the World Online
Height
3-5 ft0.9-1.5 mExtension Gardener Plant Toolbox
Spread
1.5-3 ft45-90 cmExtension Gardener Plant Toolbox
Flower
Blue, Purple/LavenderExtension Gardener Plant Toolbox
Blooms
Fall, SummerExtension Gardener Plant Toolbox
Native range
Canada, lower 48 statesPLANTS Database
Hardiness zones
4-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Loam (Silt), Sand, Shallow RockyExtension Gardener Plant Toolbox
Moisture
Good Drainage, Moist, Occasionally DryExtension 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 8 treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Low Rated by us, not by the source.

Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Cold moist stratification

    Temperature: 40°F 4°C

about 6 months from start to step 2. Germination happens during step 2, in 21 days.

70% germination in 21 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. foeniculum germ. 70L(1 1% in 5-11 d), 70D GA-3(59% in 3-7 d), 70D(none), - 40-70D(52% in 4th d), and 40-70L(42% in 4th d) using fresh seed. When part of the sample in 70D was shifted to 70L after 3w, 58% germ. in 1-3w. Seeds placed outdoors in October germ. 4% in November and 41% in April. Seeds DS 6 m at 70 germ. 70L(20%), 70 GA-3(50%), and 70D(12%), all in 2nd w, and 40(70% in 3rd w).
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 2

DerivedN. C. Deno, 1993

Difficulty Moderate Rated by us, not by the source.

Start around March 29, 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 7 days to germinate.

59% germination in 3–7 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. foeniculum germ. 70L(1 1% in 5-11 d), 70D GA-3(59% in 3-7 d), 70D(none), - 40-70D(52% in 4th d), and 40-70L(42% in 4th d) using fresh seed. When part of the sample in 70D was shifted to 70L after 3w, 58% germ. in 1-3w. Seeds placed outdoors in October germ. 4% in November and 41% in April. Seeds DS 6 m at 70 germ. 70L(20%), 70 GA-3(50%), and 70D(12%), all in 2nd w, and 40(70% in 3rd w).
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 Moderate Rated by us, not by the source.

Start around January 1, 2027 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: dark

about 3 months from start to step 2. Germination happens during step 2, in 4 days.

52% germination in 4 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. foeniculum germ. 70L(1 1% in 5-11 d), 70D GA-3(59% in 3-7 d), 70D(none), - 40-70D(52% in 4th d), and 40-70L(42% in 4th d) using fresh seed. When part of the sample in 70D was shifted to 70L after 3w, 58% germ. in 1-3w. Seeds placed outdoors in October germ. 4% in November and 41% in April. Seeds DS 6 m at 70 germ. 70L(20%), 70 GA-3(50%), and 70D(12%), all in 2nd w, and 40(70% in 3rd w).
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 September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 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. Germination time not stated; 21 days assumed.

50% germination.

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. foeniculum germ. 70L(1 1% in 5-11 d), 70D GA-3(59% in 3-7 d), 70D(none), - 40-70D(52% in 4th d), and 40-70L(42% in 4th d) using fresh seed. When part of the sample in 70D was shifted to 70L after 3w, 58% germ. in 1-3w. Seeds placed outdoors in October germ. 4% in November and 41% in April. Seeds DS 6 m at 70 germ. 70L(20%), 70 GA-3(50%), and 70D(12%), all in 2nd w, and 40(70% in 3rd w).
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 Moderate Rated by us, not by the source.

Start around January 1, 2027 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 4 days.

42% germination in 4 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. foeniculum germ. 70L(1 1% in 5-11 d), 70D GA-3(59% in 3-7 d), 70D(none), - 40-70D(52% in 4th d), and 40-70L(42% in 4th d) using fresh seed. When part of the sample in 70D was shifted to 70L after 3w, 58% germ. in 1-3w. Seeds placed outdoors in October germ. 4% in November and 41% in April. Seeds DS 6 m at 70 germ. 70L(20%), 70 GA-3(50%), and 70D(12%), all in 2nd w, and 40(70% in 3rd w).
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 High Rated by us, not by the source.

Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 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. Germination time not stated; 21 days assumed.

20% germination.

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. foeniculum germ. 70L(1 1% in 5-11 d), 70D GA-3(59% in 3-7 d), 70D(none), - 40-70D(52% in 4th d), and 40-70L(42% in 4th d) using fresh seed. When part of the sample in 70D was shifted to 70L after 3w, 58% germ. in 1-3w. Seeds placed outdoors in October germ. 4% in November and 41% in April. Seeds DS 6 m at 70 germ. 70L(20%), 70 GA-3(50%), and 70D(12%), all in 2nd w, and 40(70% in 3rd w).
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 7

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.

  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. Germination time not stated; 21 days assumed.

12% germination.

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. foeniculum germ. 70L(1 1% in 5-11 d), 70D GA-3(59% in 3-7 d), 70D(none), - 40-70D(52% in 4th d), and 40-70L(42% in 4th d) using fresh seed. When part of the sample in 70D was shifted to 70L after 3w, 58% germ. in 1-3w. Seeds placed outdoors in October germ. 4% in November and 41% in April. Seeds DS 6 m at 70 germ. 70L(20%), 70 GA-3(50%), and 70D(12%), all in 2nd w, and 40(70% in 3rd w).
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 8

DerivedN. C. Deno, 1993

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

Sow around October 2027 — a date the source gives, not one counted back from a May 3 last frost. Too late for spring 2027 — that needed starting on October 2026.

  1. Sow outdoors and leave it

    Sown outdoors in October; up in November.

No stated waiting before sowing. Then 30 days to germinate.

4% germination in 30 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. foeniculum germ. 70L(1 1% in 5-11 d), 70D GA-3(59% in 3-7 d), 70D(none), - 40-70D(52% in 4th d), and 40-70L(42% in 4th d) using fresh seed. When part of the sample in 70D was shifted to 70L after 3w, 58% germ. in 1-3w. Seeds placed outdoors in October germ. 4% in November and 41% in April. Seeds DS 6 m at 70 germ. 70L(20%), 70 GA-3(50%), and 70D(12%), all in 2nd w, and 40(70% in 3rd w).
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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