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Cornus racemosa

Gray Dogwood · Northern Swamp Dogwood

Family CornaceaeGenus Cornus

Clusters of white berries on bright red stalks, among leaves turning red at their edges
FruitMitternacht90 at English WikipediaPublic domain

About the plant

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

The plant

Habit
shrub or treePlants of the World Online
Habit
Perennial, ShrubPLANTS Database
Height
10-27 ft3-8.2 mExtension Gardener Plant Toolbox
Spread
10-15 ft3-4.6 mExtension Gardener Plant Toolbox
Flower
Gold/Yellow, WhiteExtension Gardener Plant Toolbox
Blooms
Spring, SummerExtension Gardener Plant Toolbox
Native range
Canada, lower 48 statesPLANTS Database
Hardiness zones
4-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Deep shade; Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Clay, High Organic Matter, Loam (Silt), Sand, Shallow RockyExtension Gardener Plant Toolbox
Soil pH
Acid (<6.0), Alkaline (>8.0), Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, Moist, Occasionally Dry, Occasionally WetExtension Gardener Plant Toolbox
Watering
Drought tolerance: MediumPLANTS 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.

This source reports 4 treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1993

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

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

  1. Clean the flesh off the seed

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    3 germinated in this phase.

  5. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  6. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 12 months from start to step 6. Germination happens during step 6; time not stated, 21 days assumed.

9% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Cornus p. 123Public domain
Show the original text
Cornus (Cornaceae). Seeds are always in berries so that WC was performed on all seeds before planting. Grinding ahole in the seed coat had no effect in C. racemosa gave low percent germination, but unfortunately outdoor treatment has not yet been tried and probably would have been better in view of the results with other species of Cornus. Fresh seed and DS seed gave comparable results. A 70-40- 70 pattern predominated as shown by 70-40-70(3%)-40-70(9%) for fresh seed and 70- 40-70(4%) for seed DS 6 m at 70. A preliminary 3 m at 40 had little effect as shown by 40-70-40-70(3%) for fresh seed and 40-70-40(3%)-70(5%)-40-70(5%) for seed DS 6 m at 70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Cornus p. 123. 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 Very 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. Clean the flesh off the seed

  2. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  5. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

    3 germinated in this phase.

  6. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  7. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  8. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    5 germinated in this phase.

Steps after step 6 run on after germination.

about 15 months from start to step 6. Germination happens during step 6; time not stated, 21 days assumed.

5% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Cornus p. 123Public domain
Show the original text
Cornus (Cornaceae). Seeds are always in berries so that WC was performed on all seeds before planting. Grinding ahole in the seed coat had no effect in C. racemosa gave low percent germination, but unfortunately outdoor treatment has not yet been tried and probably would have been better in view of the results with other species of Cornus. Fresh seed and DS seed gave comparable results. A 70-40- 70 pattern predominated as shown by 70-40-70(3%)-40-70(9%) for fresh seed and 70- 40-70(4%) for seed DS 6 m at 70. A preliminary 3 m at 40 had little effect as shown by 40-70-40-70(3%) for fresh seed and 40-70-40(3%)-70(5%)-40-70(5%) for seed DS 6 m at 70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Cornus p. 123. 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 Very high Rated by us, not by the source.

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

  1. Clean the flesh off the seed

  2. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  5. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 12 months from start to step 5. Germination happens during step 5; time not stated, 21 days assumed.

4% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Cornus p. 123Public domain
Show the original text
Cornus (Cornaceae). Seeds are always in berries so that WC was performed on all seeds before planting. Grinding ahole in the seed coat had no effect in C. racemosa gave low percent germination, but unfortunately outdoor treatment has not yet been tried and probably would have been better in view of the results with other species of Cornus. Fresh seed and DS seed gave comparable results. A 70-40- 70 pattern predominated as shown by 70-40-70(3%)-40-70(9%) for fresh seed and 70- 40-70(4%) for seed DS 6 m at 70. A preliminary 3 m at 40 had little effect as shown by 40-70-40-70(3%) for fresh seed and 40-70-40(3%)-70(5%)-40-70(5%) for seed DS 6 m at 70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Cornus p. 123. 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 Very 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. Clean the flesh off the seed

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  5. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 9 months from start to step 5. Germination happens during step 5; time not stated, 21 days assumed.

3% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Cornus p. 123Public domain
Show the original text
Cornus (Cornaceae). Seeds are always in berries so that WC was performed on all seeds before planting. Grinding ahole in the seed coat had no effect in C. racemosa gave low percent germination, but unfortunately outdoor treatment has not yet been tried and probably would have been better in view of the results with other species of Cornus. Fresh seed and DS seed gave comparable results. A 70-40- 70 pattern predominated as shown by 70-40-70(3%)-40-70(9%) for fresh seed and 70- 40-70(4%) for seed DS 6 m at 70. A preliminary 3 m at 40 had little effect as shown by 40-70-40-70(3%) for fresh seed and 40-70-40(3%)-70(5%)-40-70(5%) for seed DS 6 m at 70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Cornus p. 123. 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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