Deno’s GardenMy Garden

Juglans nigra

American Walnut · Black Walnut · Eastern Black Walnut

Family JuglandaceaeGenus Juglans

A single hard brown nut, deeply wrinkled and split along one seam, on a gray painted board
FruitPhoto by and (c)2007 Derek Ramsey (Ram-Man). Location credit to the Chanticleer Garden.CC BY-SA 3.0

About the plant

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

The plant

Habit
TreeExtension Gardener Plant Toolbox
Habit
treePlants of the World Online
Height
50-75 ft15-23 mExtension Gardener Plant Toolbox
Spread
50-70 ft15-21 mExtension Gardener Plant Toolbox
Flower
Gold/Yellow, GreenExtension Gardener Plant Toolbox
Blooms
SpringExtension Gardener Plant Toolbox
Native range
Canada, lower 48 statesPLANTS Database
Hardiness zones
4-9Extension 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), Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, Moist, Occasionally Dry, Occasionally Wet, Very DryExtension 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: 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 two treatments. Both are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around March 15, 2027 for a May 3 last frost.

  1. Cold moist stratification

    Temperature: 40°F 4°C

Germination happens during step 1; time not stated, 21 days assumed.

25% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Juglans p. 162Public domain
Show the original text
Juglans (Juglandaceae). J. nigra abundantly self sows here, but experiments have not been conducted as yet. Experiments were conducted on a sample of 16 seeds of a hybrid known as heartnut, 8 were sown at 70 and 8 at 40. Those sown at 40 germ. 2/8 in the 4th cycle at 70 whereas those sown at 70 germ. 2/8 in the 2nd cycle at 40. The remaining seeds ultimately rotted.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Juglans p. 162. 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 High Rated by us, not by the source.

Start around March 15, 2027 for a May 3 last frost.

  1. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Germination time not stated; 21 days assumed.

25% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Juglans p. 162Public domain
Show the original text
Juglans (Juglandaceae). J. nigra abundantly self sows here, but experiments have not been conducted as yet. Experiments were conducted on a sample of 16 seeds of a hybrid known as heartnut, 8 were sown at 70 and 8 at 40. Those sown at 40 germ. 2/8 in the 4th cycle at 70 whereas those sown at 70 germ. 2/8 in the 2nd cycle at 40. The remaining seeds ultimately rotted.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Juglans p. 162. 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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