Growing San Pedro Cactus: A Complete How-To Guide

Disclaimer: Mescaline is a largely illegal substance and we do not encourage or condone its use where it is against the law. However, we accept that illegal drug use occurs and believe that offering responsible harm reduction information is imperative to keeping people safe. For that reason, this guide is designed to enhance the safety of those who decide to use mescaline.

San Pedro is a popular South American cactus. It is one of the easiest (if not the easiest) ethnobotanical plants to grow. If gifted a cutting, all you need to do is plant it in the right kind of soil and leave it be. From there, it will grow roots and before you know it, it will be putting on new emerald green growth. In contrast, many other ethnobotanical plants can be challenging to obtain, with long hours scouring forums, not to mention the challenge of germinating them. Psychotria viridis, for example, takes six to nine months for germination. Then there is the process of keeping them alive! This is not to say San Pedro doesn’t have its challenges; however, depending on where you live, they can be a “plant and forget” species. Still, to make the most of your cactus, regular attention rewards the grower.

The mescaline-containing San Pedro cactus – Trichocereus pachanoi

The San Pedro cactus, also known as Trichocereus pachanoi or torch cactus, is a columnar cactus from South America, named and described by Britton & Rose. Also known as huachuma, it is one of many mescaline-containing cacti found throughout the Andes Mountains of Peru, Colombia, Ecuador, Bolivia, Argentina, and Chile. In recent history, San Pedro has been overshadowed by peyote, also known as Lophophora williamsii. Given the concerns around the conservation status of peyote and the preservation of cultural practices, San Pedro is often suggested as an alternative for those who are curious about mescaline.

“San Pedro” can be used to also refer to Trichocereus peruvianus (Echinopsis peruviana) or Peruvian torch, Trichocereus bridgesii (Echinopsis lageniformis) or Bolivian torch, and Trichocereus macrogonus (Echinopsis macrogona). What we know as Trichocereus pachanoi is officially known as Echinopsis pachanoi, but most collectors, cultivators, and experts on the group continue to use Trichocereus.

Trichocereus pachanoi is a ubiquitous cactus. It is used for landscaping in combination with other arid plants in minimalist gardens, and regularly sold in garden centers to many who are unaware of its entheogenic properties. However, there are those who are aware! In fact, there are Trichocereus collectors and breeders the world over. Collectors trade cactus cuttings internationally and swap seeds. The global cultivation of Trichocereus pachanoi has also led to the creation of many cultivars, including “Juul’s Giant”, “Landfill”, and, notably, the Australian “Fields” and “Yowie”. That pretty, emerald green, almost spineless columnar cactus in your neighbor’s front yard may be the sacred entheogen huachuma, the cactus used in ceremonies in South America for millennia.

The active ingredient in huachuma is the phenethylamine, mescaline. Mescaline, more specifically 3,4,5-trimethoxyphenethylamine, is a plant alkaloid; it is considered one of the classic hallucinogens alongside the psychedelic compounds LSD (derived from the ergot fungus) and psilocybin (from psilocybin mushrooms). But unlike the tryptamine alkaloids, which act on serotonin receptors, mescaline is a phenethylamine that acts on dopamine receptors, producing hallucinogenic effects. The effects of mescaline include altered thinking processes, an altered sense of time and self-awareness, and closed- and open-eye visual phenomena.

With the recent interest in microdosing, there has been interest in using mescaline for microdosing. Microdosing is the act of consuming sub-perceptual (unnoticeable) amounts of a psychedelic substance. Many individuals who have integrated microdosing mescaline into their weekly routine report higher levels of creativity, more energy, increased focus, and improved relational skills, as well as reduced anxiety, stress, and even depression. Some enthusiasts also report that microdosing mescaline has helped them heighten their spiritual awareness and enhance their senses. More information on microdosing mescaline can be found in the Ultimate Guide to Mescaline.

Why grow San Pedro?

San Pedro are beautiful cacti; they match minimalist architecture and perfectly suit concrete rock gardens when grown with other cactus plants. They grow well in dry arid environments and require little maintenance. And the flowers, well what can you say? The enormous white flowers are incredible! They first appear from the areola as small hairy balls that extend up to nine inches (23 cm) long, then burst open, with a beautiful aroma that fills your garden during the night.

They range from light green to deep emerald to dark green, sometimes with a glaucous powdery coating that can be rubbed off. The structure of the column is defined by a series of six to eight vertical ribs that are rounded in shape. The ribs give the cactus a star-like shape from above. A defining feature are the areoles that sit within transverse depressions spaced at regular intervals. Each areola looks like a small tuft of hair from which emerges between three to seven dark yellow to brown spines that can grow to three-quarters of an inch in wild specimens, although they are much shorter on cultivated plants.

It is legal to cultivate San Pedro cactus in most countries, which is why they are sold regularly in garden centers. Cultivation for consumption, however, is illegal and possession of mescaline and related compounds is illegal in most countries. Mescaline and many phenethylamines are classified as Schedule 1 drugs. This is the case in the United States, Australia, Canada, Sweden, Germany, and New Zealand, where it is currently legal to cultivate the San Pedro cactus for gardening and ornamental purposes, but not for consumption. Care should be taken with respect to how the law interprets cuttings of San Pedro, as a cutting may be interpreted as the drug.

San Pedro cactus growing tips

Cacti can be low maintenance. Generally, you can plant them and forget about them, but there are a few things to be aware of before you start growing. People often mention buying cacti and having them sit in pots and doing nothing for years, and one day finding a dried-out skeleton wondering what went wrong. There are many myths around cacti, one of them being that they don’t need much water, so let’s cover some key aspects of growing San Pedro before explaining how to propagate them.

All plants need three things: appropriate soil, the right amount of water, and light. For San Pedro specifically, the main growing season is in summer. In Equatorial Peru, they have hot summers with regular rain. In the winter, the cacti go into a hibernation phase and stop growing.

Well draining soil

Cacti need a well draining soil mix. There are many commercial cactus mixes, but they can often be too fine or with too much organic matter, which can cause problems. Hint: feel through the plastic. You want to feel small rocks, not sand. Ideally, a mix of two parts coarse sand or fine gravel to one part potting mix or broken down organic matter is best. You can also mix in slow-release nutrient pellets such as Osmocote. Some people recommend perlite, but this is not recommended as you want your soil to dry out between waterings. Be careful not to let your soil dry out too much, though; dry soil can become hydrophilic and stop soaking up water.

Ordinary potting soil is not a good match with cacti, as it sometimes doesn’t dry well and can take a while to dry out. Keep in mind that cacti need well-aerated soil and not wet, muddy soil. Cacti don’t like having their feet wet for too long. In addition to well-draining soil, make sure pots have lots of drainage holes.

Water

One of the biggest myths around cacti is that they don’t need water. This is true for some cacti.  But, in the case of Trichocereus, they love water, particularly when it is hot. However, during cold winter months, they go into a hibernation phase, and do not require a lot of water. Then they wake up early- to mid-spring. During spring, they should be watered well every month. Into summer, when it gets hot, they can be watered well every two weeks, even every week. Particularly when in pots, the soil can dry out quickly in the summer months. Water well, and when the soil has dried out, water again.

In terms of overwatering, don’t water during winter, and let your soil dry out between watering. When in pots, you can water from above, or you can sit them in a bucket for the soil to soak up water. This method works especially well if you live somewhere where water is in short supply. It takes a little practice, but when you get the rhythm right, your San Pedro will put on heaps of growth. In the peak of summer, you can see your cactus grow visibly every day.

Light

As a mature plant, San Pedro doesn’t make the best houseplant; they need lots of light and often start etiolating as they stretch towards the nearest source of light. Cacti are desert plants and can tolerate harsh direct sun. As seedlings, they prefer shade and need to slowly acclimatize to harsh sunlight, so keep them out of the full sun for the first year. If exposed to too much light, seedlings can turn red and need time to recover. If your seedlings go clear, they will not recover and will rot. Use shade or shade cloth to protect them, slowly allowing more and more exposure to full sun. This process is referred to as “hardening off”. Once acclimatized, pot them up and place them outdoors.

Note: fresh growth can sometimes sunburn, and if left sitting in window sills, they can burn quite severely. The cactus should recover in time.

Many growers, particularly in colder parts of the world, use grow lights on their cacti for the first few years to get them to size. Lights can either be sodium halide, which are used in many indoor setups, or full-spectrum LED lights. Again, slowly acclimate seedlings to the lights to not burn them.

Overwintering

Some zones do get too cold. USDA Hardiness Zones 8b to 10b are ok, as temperatures don’t drop below 15°F (-9°C). Frost or snow can severely damage the growing tip of the cactus.  When planted in the ground, some people place buckets over the top of their cacti to protect them from frost. Greenhouses work well for cacti in colder regions; they allow the heat to build up during summer and allow protection from frost and snow during winter. Some growers even heat their greenhouses during winter. If you live in a colder part of the world, one simple trick is to use  water in plastic containers painted black. The water absorbs heat during the day and then emits heat during the night.

If you live in a region that gets too cold and wet over winter and you keep your cacti in pots, you can bring them inside if you don’t have a greenhouse.

Where to start with growing San Pedro

How to grow San Pedro from cuttings

The biology of cacti is that they have a robust central column of vascular material, central pith, and tough skin to protect their flesh. Cacti are a type of succulent; they have evolved soft water-holding flesh to see them through times of no rain or moisture. The outer skin has areoles from which grow numerous thorns, the size depending on the species. When cacti reach a given height, they begin to grow offsets, e.g., branches or “pups” when grown from the cactus base. The areoles are where cacti branch or “pup” from. Many cacti grow upward as tall branched columns and, in time, the branches get heavy and become unbalanced; the hard vascular material can no longer support the weight. At a point of weakness, they can snap off.

Cacti have evolved the ability to grow roots at points where the cactus touches the ground. We can take advantage of this and, rather than waiting for branches to snap, we can cut segments from the cactus, then let them dry out or “callus” for at least two weeks. From there, you can plant the cutting in soil. This process makes cacti, particularly Trichocereus, one of the easiest plants to cultivate.

Due to this callusing and ability to grow roots from anywhere along the column, propagation of San Pedro is very easy. You can trim a cactus to any length, such as the length of your arm or the length of your palm. You just need enough to be able to plant in the soil and have enough room above the soil to grow “pups”. Even really short lengths can grow roots and then “pup” from the areoles. You can plant vertically or horizontally. Another option is to graft small sections onto fast-growing stock. San Pedro is often used to graft more potent or collectable Trichocereus for faster growth, but that’s a more advanced technique for another time.

When cutting for propagation, you don’t need long pieces. However, if you have other specific uses you might want a section that is the length of your arm. To trim your cactus, cut the stem at a 45 degree angle, so that as the cut calluses it does not create a surface for water to pool. Cut during early to mid spring. Cutting in winter invites rot and cutting in autumn prevents you from making the most of the best part of the growing season. You can trim as often as you like, depending on how much you have. As long as there are areoles, there will be pups.

The general rule: cut, callus, plant, let grow, repeat.

How to grow San Pedro from seed

Growing from seed can be a little more complicated. Trichocereus grow large fruits that contain hundreds of seeds; these break open and then distribute and can sit in the soil for a long time before the right conditions for germination appear. San Pedro cactus seeds need moist soil, humidity, and shade to germinate.

A very basic technique to germinate cactus seeds is to scatter the seeds across a bed of cactus soil in a seed raising punnet, then cover it with cling wrap to keep in moisture. Make sure it’s in a warm sunny place. One of the best techniques, popularized by Australian Trichocereus growers in the 2000s, is called the Takeaway Tek, which is based on the Fleisher method using glass jars. The Takeaway Tek is straightforward and also very effective. Using a plastic takeaway container, fill the container halfway with moist cactus soil. You can place a layer (~1 cm) of rinsed sand or zeolite on the cactus soil as a barrier to fungal infection. Then sprinkle seeds across the surface, not too close. Use a mister to mist the seeds, washing them into the soil, then place the lid on the container. Place the container somewhere warm, ideally a windowsill with some shade cloth. The seeds should sprout very quickly. This Tek is used widely due to its consistently good germination rates.

Care should be taken to not let the seeds get too much light or direct sunlight as they can die quickly, turning white or clear and rotting. Common advice is to leave them in the container for a year before transferring to pots.

Another technique is the Coke Bottle Tek developed by Halcyon Daze from the Australian website forum The Corroboree. This innovative technique takes advantage of the distinctive shape of the bottle created by the Coca-Cola company. You will need two bottles:

1. Begin by removing all the branding, then cut small 0.075-0.1 inch (2-4 mm) drainage holes approximately 1.5 to 2 inches (4-5 cm) above each indent at the bottom of the first bottle, creating five holes. Cut around the bottle approximately 3.5 inches (9 cm) from the top (just above the top flange). This is your base.
2. Cut around the second bottle approximately five inches (12.5 cm) from the bottom (just above the bottom flange). This is the top.
3. The two bottom sections of the bottle should interlock, be airtight, and hold together when lifted. The lip of the lid should be underlapping the lip of the base.
4. Fill the base bottle with a good potting mix just above the drainage holes, then fill with a good cactus soil to 4.5 to 6 inches (12-15 cm) from the base. Soak the soil in preparation for sowing seeds.
5. Place a top layer (less than half an inch; approximately 1 cm) of rinsed sand or zeolite on the cactus soil as a barrier to fungal infection. Sprinkle seeds on the top layer and mist the seeds with a mister, then attach the lid by inserting the lip of the smaller bottle half inside the base.
6. As with the Takeaway Tek, place the container somewhere warm, a windowsill or under lights, using shade cloth.

This technique is a little more complicated than the Takeaway Tek, so this resource or this video may help explain it better.

How fast does San Pedro grow?

Compared to other plants, San Pedro are not the fastest-growing plants—they require patience—but they are a very fast-growing cactus! At peak season, you can see daily growth; for much of the time, however, they can be either slow or in hibernation.

San Pedro can grow tall, up to 20 feet in height, with an individual column up to six inches in width. As a cluster of columns in an  individual plant, they can grow up to 6.5 feet in width.  Depending on region and climate, San Pedro can grow up to 12 inches per year.

Caring for your San Pedro

Cacti grow in hot and dry regions. Although they can acclimatize to various climates, they can struggle with humidity. Trichocereus grow from the desert regions of coastal Peru to just below the humid cloud forests of the Andes Mountains. Cacti tend to survive the Neglect Tek, but with a little cactus care and love, they will grow into beautiful tall specimens. Note: for alkaloid production, Neglect Tek helps.

Cacti have sharp spines and rip apart other plant foliage, so it is recommended not to plant other plants nearby. In time, cacti also start to “pup” and can start taking up more room in your garden. So you should design your garden with this in mind. If you are planting San Pedro, an area of three to six feet in diameter is best. In pots, this is not as necessary, and you can have pots right next to each other.

Due to their spines, cacti are also the kind of plants that are not very appealing to various animals or children—once bitten, twice shy. Cactus thorns are sharp and can go deep, so be careful of spines falling on the ground as they can be hard to see. Not only do they hurt and can be difficult to remove, but some people have severe reactions to the spines.

Repotting

Trichocereus will happily sit in small pots for years, but grow best when they put down large root systems. A good practice is to re-pot every couple of years. To remove them from their pot, loosen and trim their roots a little and then re-pot into a larger pot. The best way to re-pot them is to hold the cactus with one hand in the position you want it in the pot, then let the roots hang down and fill in the soil. Leave a gap at the top to allow space for watering.

Hint: while leaving room in the pots for watering, also place a layer of rocks around the cacti, such as river rocks, scoria, or gravel. Not only do they add to the visual appearance, but they also reduce weed growth. There are few things worse than weeding around cactus!

Fertilizer

Cacti do need fertilizer, not a lot though. In pots, it is best to add slow-release fertilizer pellets that break down over time. Osmocote is good, especially the type for nutrient-poor soils. Soil conditioners such as diluted Seasol also help. Cacti respond well to mycorrhizal fungi and various soil bacteria, so it helps to keep your soil healthy and well maintained.

Keep in mind that you don’t want to use anything overly chemical that the plant will absorb. Try to keep it all organic, particularly given some uses of the cactus. An excellent organic fertilizer for San Pedro is urine. Pee in a large bucket and dilute it well, then water your San Pedro occasionally with it.

Pests

One of the best things about growing cacti is that they have few pests. Snails may be a huge problem for some (though they also have weird advantages), but the main pests are scale and mealybugs.

Slugs and snails: These are not such a problem for mature cacti, but for seedlings, they can be problematic as slugs and snails often eat out the base of the seedling or eat the growing tip, munching right into the apical meristem. Having said that, there is something interesting around slug and snail slime that seems to result in the occasional mutant. Deterring slugs and snails can be a challenge, but copper tape, beer traps, and even sand help deter their meanderings.

Scale: Scale are small insects that resemble small cottony tufts or dome-shaped shells. They can hide quite easily. They love cacti and can hide easily between the ribs. They particularly like the younger flesh near the meristem, where it is easy to insert their proboscis and suck on the sap. The best way to solve the problem is to crush them with your fingernail or use a little warm water and biodegradable detergent, brushing them off with a toothbrush. Keep in mind that knocking them off means they can climb back up the cactus.

Red spider mites: Red spider mites will often appear on San Pedro but will not pose any significant problems unless the cactus is very unhealthy with dry or rotting roots. They cause damage to cacti by sucking plant sugars. The first sign is usually thin threads resembling spiderwebs. Spider mites are very small, red in color, resembling fine particles of dust or dirt.  Spider mites are a sign of a stressed plant, and they are attracted by yellowing of the plant, which is a common sign of nutrient deficiency. Simply wipe off the infestation and give the plant some love and attention.

Fungus gnats: These are little black flies that resemble mosquitoes. They are often seen hovering around plants or on the soil. The flies do not cause any damage but the larva that live in the soil damage the roots. Large plants are usually not affected, but seedling growth may be stunted by the root damage. Fungus gnats are attracted by fungus in the soil, and are a sign that your soil is way too wet and not draining correctly.

Mealybugs: Mealybugs have a white and cottony appearance. They usually live in clusters, hiding between ribs. Root mealybugs live in the soil and resemble white deposits on the roots. They cause damage by sucking plant sugars from the roots, making the plant more susceptible to rot from bacterial and fungal infections. Neem oil is a good treatment for these, and the use of diatomaceous earth is great as a surface coating.

Other issues

Damping-off: Damping-off is a soil fungus that can affect the seedlings of any plant. It happens in seedlings when the plants are too close and there is a lack of airflow. It tends to rot out the base of the stems, destroying the plant. In some cases, you can rescue a cactus that has been hit with damping-off. If it is old enough, it can survive on its own without roots while the wound calluses over.

Black spots: Black spots can sometimes appear on your San Pedro in humid or overly moist conditions. They don’t do any damage and can be ignored. In time they will callous and turn white. They result in marks that affect appearance, but not the overall health of the plant.

Rot: Rot can be a problem. Cactus flesh is soft with lots of water, the perfect breeding ground for some fungi that can happily run through cactus flesh. Rot can appear either orange or brown. Rot is best solved by cutting out the rotting section, letting the wound callus, or treating with sulfur, or, for a more natural solution, cinnamon.

Witch’s broom disease: Witch’s broom is a virus that messes with the growing meristems of plants. It makes a plant suddenly start branching uncontrollably. In San Pedro, this results in weird mutations and multiple uncontrolled growths. Initially, it can look cool, but the virus can spread to the rest of your collection. With plant viruses, they generally cannot be cured. In the case of witch’s broom, there is only one solution. You can remove the plant to another location, but it will always put other plants at risk. The best advice is to destroy the plant; even if it is something special, there is no point putting the rest of your collection at risk.

Reaping the rewards

With care and attention, San Pedro rewards the grower in time. While not fast growing, they have other lessons for the grower: patience and appreciation. Quite often, growers get to a point where the idea of cutting their cactus feels a little uncomfortable, particularly in the case of rare clones or seed-grown specimens.

San Pedro are a common species and their cultivation, if not careful, leads to growing and collecting a huge variety of other types, including named clones, other species, the mutants, and other plants entirely. With so many possibilities, growing cacti becomes an incredibly rewarding hobby.