Central Mexico Pipe Organ, Organo, Fence Post Cactus

Pachycereus marginatus

Family: Cactaceae (kak-TAY-see-ee) (Info)
Genus: Pachycereus (pak-ee-KER-ee-us) (Info)
Species: marginatus (mar-jen-AY-tus) (Info)
Synonym:Cereus marginata
Synonym:Stenocereus marginatus
Synonym:Lemaireocereus marginatus
Synonym:Cereus gemmatus
Synonym:Stenocereus marginatus var. gemmatus
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Cactus and Succulents

Foliage Color:


Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Drought-tolerant; suitable for xeriscaping

Where to Grow:

Unknown - Tell us


4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)

12-15 ft. (3.6-4.7 m)

15-20 ft. (4.7-6 m)


3-6 in. (7-15 cm)

6-9 in. (15-22 cm)

9-12 in. (22-30 cm)


USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Full Sun


Plant has spines or sharp edges; use extreme caution when handling

Bloom Color:


Bloom Time:

Late Winter/Early Spring

Mid Spring




Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

From woody stem cuttings

From softwood cuttings

Allow cut surface to callous over before planting

From seed; direct sow after last frost

Seed Collecting:

Allow unblemished fruit to ripen; clean and dry seeds

Unblemished fruit must be significantly overripe before harvesting seed; clean and dry seeds

Properly cleaned, seed can be successfully stored


This plant has been said to grow in the following regions:


Gilbert, Arizona

Green Valley, Arizona

Maricopa, Arizona

Phoenix, Arizona (2 reports)

Queen Creek, Arizona

Tucson, Arizona

Agoura Hills, California

Brentwood, California

Canoga Park, California

Casa De Oro-mount Helix, California

Hayward, California

Reseda, California

San Diego, California

San Marino, California

Sherman Oaks, California

Spring Valley, California

Stevinson, California

Thousand Oaks, California

Hudson, Florida

Metairie, Louisiana

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Gardeners' Notes:


On Feb 12, 2015, poeciliopsis from Phoenix, AZ wrote:

Central Phoenix -- It is interesting, given the other comments on Mexican fence post cactus, that I have never experienced scale on any of mine. Two of mine grow with their lower 3-5 feet in partial shade and with water lapping at their base during our flood irrigation every other week from March to November. Despite that they do well, although the tallest, which had reached about 15 feet, had to have it's top cut off after a serious windstorm gave it a decided lean that kept increasing. Mexican fence post cactus makes a great plant for a small area because it is to linear. We have some of them in a narrow bed between the driveway and an east-facing block wall. Despite the harsh environment they do well, even with sporadic water.


On Mar 11, 2012, growin from Beautiful, BC (Zone 9b) wrote:

Nice cactus but seems very susceptible to scale which the plant will eventually succumb to. The reddish blooming form in more common in horticulture but I believe the green/yellow blooming form is more common in habitat.


On Jul 29, 2005, Xenomorf from Valley of the Sun, AZ (Zone 9b) wrote:

Another synonym is Marginatocereus marginatus. Other common names are: Chilayo, Mexican Fence Post, Organ Cactus & rgano.


On Feb 17, 2004, palmbob from Acton, CA (Zone 8b) wrote:

Very neat, straight up and down column, sometimes branching cactus with small spines along linear rows up and down the plant. The surface is slightly rough to the feel, like sandpaper. Light green in color. Used for barriers in Mexico (a wall of these is hard to get through and/or see through).

Plant is prone to scale if grown at all in the shade. Scale, and virtually any sort of insult will permanently scar this cactus easily.