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Tsuga canadensis

Black Hemlock · Canada Hemlock · Canadian Hemlock · Eastern Hemlock

Family PinaceaeGenus Tsuga

A tall conifer with a feathery open crown and short drooping branchlets, against a clear blue sky.
The whole plantBruce MarlinCC BY-SA 3.0

About the plant

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

The plant

Habit
treePlants of the World Online
Habit
Perennial, TreePLANTS Database
Height
40-70 ft12-21 mExtension Gardener Plant Toolbox
Spread
25-35 ft8-11 mExtension Gardener Plant Toolbox
Flower
YellowPLANTS Database
Blooms
Mid SpringPLANTS Database
Native range
Canada, lower 48 statesPLANTS Database
Hardiness zones
3-7Extension Gardener Plant Toolbox

Growing conditions

Sun
Dappled Sunlight; Deep shade; Partial ShadeExtension Gardener Plant Toolbox
Soil
Clay, Loam (Silt), SandExtension Gardener Plant Toolbox
Soil pH
Acid (<6.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, MoistExtension Gardener Plant Toolbox
Watering
Drought tolerance: LowPLANTS 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; Extension Gardener Plant Toolbox — NC State Extension.

Worth knowing

Two sources report 7 treatments between them. All are shown.

Protocol 1

DerivedN. C. Deno, 1996

Difficulty Low Rated by us, not by the source.

Start around July 16, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 15, 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 84 days.

70% germination in 84 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Tsuga p. 83Public domain
Show the original text
Tsuga (Pinaceae). T. canadensis showed a curious effect on DS at 70. Fresh seeds germ. 70D-40(5%)-70(31% in 1-5 w) and 40(68% in 12th w)-70(11%). Seeds DS 6 m germ. 70D(10% in 12th w)-40(none) and 40(70% in 12th w). Seeds DS 12 m germ. 70D(all,rotted) and 40-70D(23% in 3rd w). Seeds DS 2 y germ. 4Ö-70D{4%) and 70D-40(4%)-70D(23% in 3rd w), and seeds DS 3 y were dead. The interpretation is that the seeds are dying in DS. After 12 m of DS the seeds require increasing times at 40 before they will germinate.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Tsuga p. 83. 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, 1996

Difficulty Moderate Rated by us, not by the source.

Start around January 11, 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

    11 germinated in this phase.

Steps after step 1 run on after germination.

Germination happens during step 1, in 84 days.

68% germination in 84 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Tsuga p. 83Public domain
Show the original text
Tsuga (Pinaceae). T. canadensis showed a curious effect on DS at 70. Fresh seeds germ. 70D-40(5%)-70(31% in 1-5 w) and 40(68% in 12th w)-70(11%). Seeds DS 6 m germ. 70D(10% in 12th w)-40(none) and 40(70% in 12th w). Seeds DS 12 m germ. 70D(all,rotted) and 40-70D(23% in 3rd w). Seeds DS 2 y germ. 4Ö-70D{4%) and 70D-40(4%)-70D(23% in 3rd w), and seeds DS 3 y were dead. The interpretation is that the seeds are dying in DS. After 12 m of DS the seeds require increasing times at 40 before they will germinate.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Tsuga p. 83. 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, 1996

Difficulty High Rated by us, not by the source.

Start around September 3, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 2, 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

    5 germinated in this phase.

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 6 months from start to step 3. Germination happens during step 3, in 35 days.

31% germination in 7–35 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Tsuga p. 83Public domain
Show the original text
Tsuga (Pinaceae). T. canadensis showed a curious effect on DS at 70. Fresh seeds germ. 70D-40(5%)-70(31% in 1-5 w) and 40(68% in 12th w)-70(11%). Seeds DS 6 m germ. 70D(10% in 12th w)-40(none) and 40(70% in 12th w). Seeds DS 12 m germ. 70D(all,rotted) and 40-70D(23% in 3rd w). Seeds DS 2 y germ. 4Ö-70D{4%) and 70D-40(4%)-70D(23% in 3rd w), and seeds DS 3 y were dead. The interpretation is that the seeds are dying in DS. After 12 m of DS the seeds require increasing times at 40 before they will germinate.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Tsuga p. 83. 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, 1996

Difficulty High Rated by us, not by the source.

Start around December 21, 2026 for a May 3 last frost. Too late for spring 2027 — that needed starting on December 20, 2025.

  1. Dry storage

    Duration: 360 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: dark

about 15 months from start to step 3. Germination happens during step 3, in 21 days.

23% germination in 21 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Tsuga p. 83Public domain
Show the original text
Tsuga (Pinaceae). T. canadensis showed a curious effect on DS at 70. Fresh seeds germ. 70D-40(5%)-70(31% in 1-5 w) and 40(68% in 12th w)-70(11%). Seeds DS 6 m germ. 70D(10% in 12th w)-40(none) and 40(70% in 12th w). Seeds DS 12 m germ. 70D(all,rotted) and 40-70D(23% in 3rd w). Seeds DS 2 y germ. 4Ö-70D{4%) and 70D-40(4%)-70D(23% in 3rd w), and seeds DS 3 y were dead. The interpretation is that the seeds are dying in DS. After 12 m of DS the seeds require increasing times at 40 before they will germinate.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Tsuga p. 83. 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, 1996

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, 2024.

  1. Dry storage

    Duration: 730 daysTemperature: 70°F 21°C

  2. Warm moist stratification

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

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    4 germinated in this phase.

  4. Warm moist stratification

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

about 2.5 years from start to step 4. Germination happens during step 4, in 21 days.

23% germination in 21 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Tsuga p. 83Public domain
Show the original text
Tsuga (Pinaceae). T. canadensis showed a curious effect on DS at 70. Fresh seeds germ. 70D-40(5%)-70(31% in 1-5 w) and 40(68% in 12th w)-70(11%). Seeds DS 6 m germ. 70D(10% in 12th w)-40(none) and 40(70% in 12th w). Seeds DS 12 m germ. 70D(all,rotted) and 40-70D(23% in 3rd w). Seeds DS 2 y germ. 4Ö-70D{4%) and 70D-40(4%)-70D(23% in 3rd w), and seeds DS 3 y were dead. The interpretation is that the seeds are dying in DS. After 12 m of DS the seeds require increasing times at 40 before they will germinate.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Tsuga p. 83. 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, 1996

Difficulty High Rated by us, not by the source.

Start around July 16, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on July 15, 2026.

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Warm moist stratification

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

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

Steps after step 2 run on after germination.

about 6 months from start to step 2. Germination happens during step 2, in 84 days.

10% germination in 84 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Tsuga p. 83Public domain
Show the original text
Tsuga (Pinaceae). T. canadensis showed a curious effect on DS at 70. Fresh seeds germ. 70D-40(5%)-70(31% in 1-5 w) and 40(68% in 12th w)-70(11%). Seeds DS 6 m germ. 70D(10% in 12th w)-40(none) and 40(70% in 12th w). Seeds DS 12 m germ. 70D(all,rotted) and 40-70D(23% in 3rd w). Seeds DS 2 y germ. 4Ö-70D{4%) and 70D-40(4%)-70D(23% in 3rd w), and seeds DS 3 y were dead. The interpretation is that the seeds are dying in DS. After 12 m of DS the seeds require increasing times at 40 before they will germinate.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Tsuga p. 83. 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 Low 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 April.

No stated waiting before sowing. Then 180 days to germinate.

74% germination in 180 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Tsuga p. 226Public domain
Show the original text
Tsuga (Pinaceae). T. canadensis germ. 40(68% in 12th w)-70(11% on 2nd d), 70(GA-3)-40(70% in 2-12 w), 70L(2%)-40(7%)-70(43%), and 70D-40(2%)- 70D(11%). Seeds placed outdoors in October germ. 74% in April.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Tsuga p. 226. 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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