One of my favorite plants in my garden is a Column Cactus, Columnar Cacti. Columnar cacti earned their common name from the slender shape and erect growth habit they exhibit.
There are several unrelated species known by the common name columnar cacti, including old man cactus (Cephalocereus senilis), firecracker cactus (Cleistocactus smaragdiflorus) and giant saguaro (Carnegiea gigantea). I am fairly certain that my cacti is know as a San Pedro cactus, also called Trichocereus pachanoi or Echinopsis pachanoi. It grows up to a foot a year and can reach up to 20 feet. It has 6 to 8 ribs and can branch usually as side arms. Its flowers on short stems with black hairs leading to a large multi-petal white flowers. The fruit is oblong and green turning to pinkish red when it is ripe.
It is native to the Andes of Peru and Ecuador at an altitude of 6,600 to 9,800 ft. Because of the high altitude and with high rainfall in its native environment, it can withstand temperatures far below that of many other cacti. It prefers fertile, well drained soil for healthy growth. It is considered a psychoactive cacti. Most psychoactive cacti contain mescaline as their primary active chemical. It is legal to cultivate them in the United States as long as they are not intended for human consumption.
When I first moved to Houston 17 years ago I still had things in California in storage. On one trip I brought back a little 8 inch tall Column Cactus that need some TLC. I planted it in a terracotta pot and set it in a sheltered corner just outside my kitchen. With all the rain here I rarely watered it. I did start watering it weekly during the worst years of our drought. For the longest time it’s was a singular column that grew taller and taller. By the time I realized I need to change the pot it was well rooted in.
Saint Pedro’s Cactus, Echinopsis pachonoi have been used in traditional Andean medicine and religious practices for at least two thousand years. Evidence in Archeological site found dried cactus rolled up in a tubular cigar shapes. A Chavín stone carving from a temple at Chavín de Huantar in northern Peru, dated to around 1300 B.C., shows their principal deity holding what looks like an Echinopsis pachonoi. The Roman Catholic Church tried to suppress its use after the Spanish conquest but this appears to have failed because of its name, Saint Pedro cactus. Thought to be named after Saint Peter because like Saint Peter it holds the keys to heaven.
If you are interested in more information you might check out Columnar Cati and online organization dedicated to Column Cati. They have an amazing collection of material with a good database of photographs.

And just this morning when I went to take a picture of the whole cacti I found it is missing an arm.
I took the arm and made a clean cut at an angle and will let it dry until it heals and hardens off. It may take up to two weeks. Best to leave it in a dry shady place with good airflow. This is so that the surface of the cut end dries out like paper forming a seal to keep out microbes such as fungi and bacteria. Then I will pot in in a container of sandy potting soil and see if I can get it to root. I will have to keep it slightly damp but protect it from becoming overly wet because then it can rot. It will need bright light and warmth but not direct light until it is rooted. Direct sun can dry out the flesh too much while it is trying to grow roots. Then I can gradually get it use to more and more direct sun. And then what to do with it. I am also going to see about planting the seeds that appear to be in the fruit. Perhaps just put the fruit on top of some soil and let it do what it would do naturally.
Happy Gardening!
The flower is amazing, my cacti are barely getting 3 hours of direct sunlight everyday, so I’m thinking they should be getting more.
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I think morning light for 4-6 hours would be good! I love how it flowers in late summer a real treat.
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It looks very similar to my night blooming cactus, Selenicereus grandiflorus which smells wonderful, although the plant gets bigger and uglier every year.
Your plant is more upright and neater. Are the flowers fragrant?
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I have a couple of night blooming cacti and they don’t bloom as profusely as this one. The flowers didn’t really smell much and they last longer than the night blooming cacti.
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What a treasure! And now you will have two. =) I really like the look of the plant itself but that flower is truly lovely. Fluffy and white on dark green. Thanks for the background stories, too. Great post.
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Thank you Debra, It is a treasure here in Houston because not many cacti like our clay soil and 50+ inches of rain. These seem quite at home.
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So that arm just broke off, it wasn’t broken by an evil doer? Wonderful plant with a very sexy flower!
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We had a big wind with strong gusts that took down tree limbs and up rooted a few trees. I think this arm was a victim of the wind! Now to see if I can root it : )
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What a beautiful cactus! It’s a form of Cereus species cactus, not an Echinopsis/Trichocereus pachanoi. Notice that your plant has no hairs on the flower but the description for T. pachanoi includes black hair on the flower stems. Trichocereus means ‘hairy cereus’ all Trichocereus cactuses have hairy flowers. Cereus cactuses all have smooth hairless flowers.
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It might honestly be a Cereus Cactus. I have one just like it and I found out mine is a Cereus not a San Pedro cactus
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Perhaps you are right. I can’t go check again. We had a horrible 2 day 18 degree freeze and it died. I would have cut some off if I realized it would not survive. It had been in the ground 18 years. I found this interesting comparison post https://sacredcactus.com/comparisons.htm
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If you’d like a replacement San Pedro from California let me know. I’ll ship one out no charge. 🤙🏼🌵🔑
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That is very generous. I am happy to pay, do you have a website. I would not like to put my address here.
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I’ve got a website at CactusAffinity dot com but I’m not set up for sales there anymore. You should be able to find my email there if you’d like to get in contact.
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