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Hypericum perforatum

Common St. John's Wort · Gammock · Goatweed · Common St. Johnswort

Family HypericaceaeGenus Hypericum

A yellow flower with a wide boss of stamens, its petals edged with small black dots
FlowerDidier DescouensCC BY-SA 4.0

About the plant

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

The plant

Habit
Ground Cover, Perennial, WildflowerExtension Gardener Plant Toolbox
Habit
perennialPlants of the World Online
Height
1-3 ft30-90 cmExtension Gardener Plant Toolbox
Spread
0.8-2 ft25-60 cmExtension Gardener Plant Toolbox
Flower
Gold/YellowExtension Gardener Plant Toolbox
Blooms
Spring, SummerExtension Gardener Plant Toolbox
Native range
Albania, Altay, Austria, Baltic States, Belarus, Belgium and elsewhereGBIF Backbone Taxonomy
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
Soil pH
Acid (<6.0), Alkaline (>8.0), 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; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

  • It was harvested at the Midsummer festival, later St John's Day on 24 June, when its healing and magical powers were thought strongest; hence St John's wort. Wikipedia: Hypericum perforatum
  • Hypericum may come from the Greek for above a picture, from the custom of hanging it over religious icons. Translucent glands make the leaves look perforated. Wikipedia: Hypericum perforatum

This source reports 5 treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty Low Rated by us, not by the source.

Start around September 10, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 9, 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 28 days to germinate.

100% germination in 7–28 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hypericum p. 154Public domain
Show the original text
Hypericum (Hyperiaceae). H. perforatum, it is possible that germination would have been higher in light. H. perforatum germ. 70L(90-100% in 1-4 w), 70D GA-3(100% in 1-4 w), 70D(20- 40% in 1-4 w), and 40-70L(10-35%) using seed DS 6 m at 70. Fresh seed germ. 70D- 40-70L(100%) and 70D-40-70D(none). The photorequirement dies away with DS.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hypericum p. 154. 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 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.

  1. Warm moist stratification

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

  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 6 months from start to step 3. Germination happens during step 3; time not stated, 21 days assumed.

100% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hypericum p. 154Public domain
Show the original text
Hypericum (Hyperiaceae). H. perforatum, it is possible that germination would have been higher in light. H. perforatum germ. 70L(90-100% in 1-4 w), 70D GA-3(100% in 1-4 w), 70D(20- 40% in 1-4 w), and 40-70L(10-35%) using seed DS 6 m at 70. Fresh seed germ. 70D- 40-70L(100%) and 70D-40-70D(none). The photorequirement dies away with DS.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hypericum p. 154. 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 September 10, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 9, 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 28 days to germinate.

90% germination in 7–28 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hypericum p. 154Public domain
Show the original text
Hypericum (Hyperiaceae). H. perforatum, it is possible that germination would have been higher in light. H. perforatum germ. 70L(90-100% in 1-4 w), 70D GA-3(100% in 1-4 w), 70D(20- 40% in 1-4 w), and 40-70L(10-35%) using seed DS 6 m at 70. Fresh seed germ. 70D- 40-70L(100%) and 70D-40-70D(none). The photorequirement dies away with DS.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hypericum p. 154. 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 September 10, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 9, 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. Then 28 days to germinate.

20% germination in 7–28 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hypericum p. 154Public domain
Show the original text
Hypericum (Hyperiaceae). H. perforatum, it is possible that germination would have been higher in light. H. perforatum germ. 70L(90-100% in 1-4 w), 70D GA-3(100% in 1-4 w), 70D(20- 40% in 1-4 w), and 40-70L(10-35%) using seed DS 6 m at 70. Fresh seed germ. 70D- 40-70L(100%) and 70D-40-70D(none). The photorequirement dies away with DS.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hypericum p. 154. 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 June 19, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 18, 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; time not stated, 21 days assumed.

10% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hypericum p. 154Public domain
Show the original text
Hypericum (Hyperiaceae). H. perforatum, it is possible that germination would have been higher in light. H. perforatum germ. 70L(90-100% in 1-4 w), 70D GA-3(100% in 1-4 w), 70D(20- 40% in 1-4 w), and 40-70L(10-35%) using seed DS 6 m at 70. Fresh seed germ. 70D- 40-70L(100%) and 70D-40-70D(none). The photorequirement dies away with DS.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hypericum p. 154. 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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