Ferocactus cylindraceus

🌵 Care at a glance
Light	Full sun; the more the better once established
Water	Sparingly; soak then let dry out completely, keep dry in winter
Soil	Very fast-draining mineral mix (see Soil and potting mix)
Temperature	Heat-loving; hardy to around −7 °C when bone dry, USDA zones 9–11
Propagation	Seed
Toxicity	Non-toxic to cats and dogs, though the stiff spines can injure

Ferocactus cylindraceus is a tall, cylindrical barrel cactus of the Mojave and Sonoran deserts of the southwestern United States and northwestern Mexico, clothed in dense, curving spines that range from bright red through pink to yellow. Known widely as the California barrel cactus, it is one of the classic "barrels" of the American desert, often seen leaning conspicuously toward the south or southwest on rocky slopes and canyon walls. It belongs to the genus Ferocactus, the aptly named "fierce cacti".

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Description

Ferocactus cylindraceus begins life as a squat globe and lengthens with age into a stout column, commonly reaching around 1 m tall and 30–40 cm across, and occasionally taller in old, undisturbed plants. The body is deeply ribbed, and each areole bears a formidable armament: several stout, flattened central spines — one of which is typically long, flattened, curved and often twisted — surrounded by finer, bristle-like radials. Spine colour is variable and often spectacular, shading from red and rose to straw-yellow, and the spines frequently obscure the green stem beneath.

Bell-shaped flowers appear in a ring around the crown in late spring and summer, in yellow to orange tones, sometimes flushed red. These are followed by fleshy, yellow, scaly fruits that persist on the plant and are an important food source for desert wildlife.

Older plants often lean markedly toward the south or southwest, a phototropic habit that has earned barrels like this the nickname "compass cactus".

Distribution and habitat

The species is native to the Mojave and Sonoran deserts, ranging across southeastern California, southern Nevada, Arizona and Utah in the United States and into Baja California and Sonora in Mexico. It favours rocky desert slopes, gravelly washes, canyon walls and bajadas, usually in well-drained coarse soils and full exposure, where summer heat is intense and rainfall is sparse and seasonal.

As with all cacti, Ferocactus cylindraceus is listed under CITES Appendix II, and wild plants are protected on public lands; collecting from habitat is illegal. Nursery-grown, seed-raised plants are widely available and entirely legal to own and trade.

Cultivation

This is a tough, sun-loving barrel that is easy to please as long as its roots are kept sharply drained. Grow it in a very gritty, mostly mineral mix in a container with ample drainage, or in the open ground in hot, dry climates. Give it as much direct sun as you can — full exposure brings out the strongest spine colour and keeps the body squat and firm rather than pale and drawn.

Water generously during the warm growing season, letting the soil dry out completely between soakings, then keep the plant dry and unwatered through winter. Excess water, poor drainage or a stagnant, cold-and-wet dormancy are the quickest ways to kill it. In regions with wet winters, overwintering under cover or in an unheated glasshouse is wise; kept dry, established plants tolerate light frost. See Watering and Repotting for general technique, and handle with care — the stout central spines catch skin and clothing readily.

Propagation

Seed is effectively the only method, as the species remains solitary and does not offset. Sow the fine seed on a warm, mineral surface kept humid until germination, then grow the seedlings on hard in bright light. Barrels are slow, and patience is required in the early years; see Propagation — seed for a full walkthrough.

Common problems

Rot — the usual killer, brought on by overwatering, a slow-draining mix, or water sitting on the crown; the plant softens and discolours, often from the base.
Etiolation — too little light makes the stem pale, soft and elongated, and dulls the spine colour.
Corky scarring — sunstroke or cold damage can leave permanent tan or brown patches on the body; move plants into strong sun gradually after winter.
Pests — mealybugs (white fluff among the areoles) and, under glass, red spider mites are the most common; see Pests and diseases.

References

Horticultural information for growing these plants as ornamentals. Always confirm plant identification and any handling, grafting, or safety advice against authoritative sources before acting.