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Aesculus hippocastanum

Conker-tree · European Horse Chestnut · Horse Chestnut

Family SapindaceaeGenus Aesculus

Also published as Aesculus hippocasteanum. You are in the right place.

A large domed tree in full leaf standing beside farm buildings
The whole plantStephan van HeldenCC BY-SA 4.0

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
40-70 ft12-21 mExtension Gardener Plant Toolbox
Flower
Gold/Yellow, Red/Burgundy, WhiteExtension Gardener Plant Toolbox
Native range
Albania, Bulgaria, Greece, NW. Balkan Pen., Turkmenistan, TürkiyeGBIF Backbone Taxonomy
Hardiness zones
4-7Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Moisture
Good DrainageExtension 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

  • The seeds are conkers, used in the British and Irish children's game. In World War I people were asked to collect them as a source of starch for making acetone, used to produce cordite. Wikipedia: Aesculus hippocastanum
  • A horse chestnut stood outside the window of Anne Frank's secret annex in Amsterdam and appears in her diary. It survived until a heavy wind blew it over in August 2010. Wikipedia: Aesculus hippocastanum

This source reports three treatments. All are shown.

Protocol 1

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around February 4, 2027 for a May 3 last frost.

  1. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 60 days to germinate.

20% germination in 30–60 days.

The seedlings do not develop properly. The cold period is worth the wait.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Aesculus p. 89Public domain
Show the original text
If sown at 70, 20-30% germ. in 1-2 m, but the seedlings do not develop properly. Seed DS 6 m at 70 is dead.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Aesculus 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 Low Rated by us, not by the source.

Start around December 29, 2026 for a May 3 last frost.

  1. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  2. Sow and cover

    Temperature: 70°F 21°C

about 3 months from start to sowing. Then 7 days to germinate.

Germinates in 1–7 days.

Deno's percentage is printed "109%" and cannot be read. The three months at 40 can be moist or dry: the seeds are large enough to carry their own moisture.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Aesculus p. 89Public domain
Show the original text
Aesculus (Hippocastanaeae). A. hippocasteanum and A. pavia behaved identically and germ. 40-70 (109% in 1-7 d). The first 3 m at 40 can be conducted either moist or dry. Apparently there is enough moisture in these large seeds so that DS at 40 has the same effect as placing in moisture at 40.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Aesculus 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

  1. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C

about 6 months from start to sowing.

0% germination.

Six months of dry storage at 70 kills the seed.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Aesculus p. 89Public domain
Show the original text
If sown at 70, 20-30% germ. in 1-2 m, but the seedlings do not develop properly. Seed DS 6 m at 70 is dead.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Aesculus p. 89. Quoted exactly. Every value on this card comes from this record; 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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