Mendel’s Gardens

Ferocactus cylindraceus

California Barrel Cactus · Compass Barrel

Family CactaceaeGenus Ferocactus

Also published as Ferocactus acanthoides, Ferocactus acanthodes. You are in the right place.

About the plant

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

Habit
Perennial, ShrubPLANTS Database
Native range
Native to the lower 48 statesPLANTS Database
Note
WFO treats acanthodes as the accepted name; GBIF and SID do not.GBIF Backbone Taxonomy

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: PLANTS Database — USDA NRCS; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

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

Protocol 1

DerivedSER, INSR and RBG Kew, 2026

Difficulty Moderate Rated by us, not by the source.

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

  1. Sow on the surface — do not cover

    Temperature: 79°F 26°C Light: eitherMedium: 1% agarAmount: 101 mg/l KNO3

    12 hours light, 12 dark.

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

70% germination.

Six times Deno's figure, at 79F rather than 70F. The record is the variety lecontei.

Seed Information Database — SER, INSR and RBG Kew, 2026 · Germination records, ser-sid.orgCreative Commons Attribution — reused with credit
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Ferocactus cylindraceus var. lecontei · 70% germination · sample size 10 · 1% agar with 101mg/l Potassium Nitrate (KNO3) · 12/12 light hours · 26°C · USA
Seed Information Database, Germination records, ser-sid.org. 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 8, 2027 for a May 3 last frost.

  1. Gibberellic acid soak

  2. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 28 days to germinate.

12% germination in 7–28 days.

Deno's experiment was only six weeks old when he wrote it up.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, FerocactusPublic domain
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Ferocactus (Cactaceae). GA-3 was required. Expts. are only 6 w old. F. acanthoides germ. 70 GA-3(12% in 1-4 w) and none in 70D. F. wislizenii germ. 70 GA-3(8% in 4th w) and none in 70D.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Ferocactus. 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. Sow and cover

    Temperature: 70°F 21°C Light: dark

    None germinated.

No stated waiting before sowing.

0% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, FerocactusPublic domain
Show the original text
Ferocactus (Cactaceae). GA-3 was required. Expts. are only 6 w old. F. acanthoides germ. 70 GA-3(12% in 1-4 w) and none in 70D. F. wislizenii germ. 70 GA-3(8% in 4th w) and none in 70D.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Ferocactus. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list.