San Pedro Cactus
The San Pedro Cactus is a wonderful plant to add to any garden collection and a great cactus for beginners. These hardy cacti survive in a wide range of conditions and thrive in most home environments.
Furthermore, they have a unique blue tint that makes them pop when planted next to other cacti.
Check out our other page for information on growing succulent rock gardens: How to Make a Succulent Rock Garden.
Table of Contents:
Care and Maintenance Information
Quick Care Infographic:
Keep reading to learn more or visit or webpage at San Pedro Cactus Care Infographic to see a breakdown of the provided information.
Background Information:
The scientific name for the San Pedro Cactus is Echinopsis pachanoi. They are actually a distant relative to the Peanut Cactus (Echinopsis chamaecereus), but they are just as interesting.
(Check out our Peanut Cactus Care Guide if interested)
The San Pedro Cactus grows naturally in the Andes Mountains of South America. They are native to the following countries: Argentina, Bolivia, Chile, Colombia, Peru, and Ecuador.
The cactus has historically been used as a traditional medicine in South America. This is most likely because the cactus contains mescaline, a semi-powerful psychedelic; however, mescaline is also used treat fevers and muscle aches.
It is grown across the world to be used as a decorative cactus and is used in grafting. (Grafting is the process of joining plants together as one plant and helps speed up growth.)
Appearance:
The San Pedro Cactus is a tall and tube-like cactus. Young plants are often light to dark green, but well-established plants take on a faint blue color.
Its branches look like elongated 6 or 8 pointed stars, and each rib has spines running up its sides. However, some varieties have small spines or lack them altogether.
The plants grow anywhere from 10 to 20 feet (3-6 meters) high, and they can grow up to 6 feet (2 meters) wide from the base.
San Pedro Cactus General Care:
This cactus requires the same general care as most succulents and cacti. It thrives with plenty of light, warm temperatures, and dry environments.
San Pedro Cactus Temperature Requirements:
Because they live high in the mountains, this cactus has adapted to survive large temperature swings. This makes it more resilient than most other cacti.
They can survive sustained winter temperatures of 50°F (10°C), but they can survive dips as low as 19°F (-7°C).
However, keep in mind that subjecting them to temperatures this low consistently will greatly decrease their chances of survival and slow their growth.
On the opposite side of the temperature spectrum, these plants easily survive over 100°F (38°C) for a short period of time.
They do best when sustained at room temperature, or at about 70°F (21°C). This makes them ideal for a life indoors or in warm climates.
Additionally, make sure to never place cacti in drafty areas. Although they are more resilient to drafts and wind than other plants, they can still get windburn, dry out, or become chilled.
San Pedro Cactus Light Requirements:
Like most other cacti, the San Pedro Cactus needs a lot of light in order to thrive. The best option is to provide plenty of natural light for the cactus.
Older cacti do best in full sunlight or partial shade, whereas young and fragile cacti require shade during the afternoon when the sun is most intense. They do best with around 6-8 hours of full sun every day.
Sometimes it is impossible to grow the cactus outdoors because it is too cold. Placing the plant near a southern facing window (northern if you live in the southern hemisphere) will provide it with enough light to grow.
If the cactus becomes stretched out or stops growing, it may need more light. Fluorescent or grow lights are perfect for supplementing plants with enough light to grow faster and healthier.
If using grow lights, keep them on for about 14-16 hours a day with about 12 inches (30 centimeters) of space between the top of the plant and the light.
Water Requirements:
Like most other cacti, the San Pedro Cactus does not require a lot of water. They are capable of surviving extended periods of drought without taking permanent damage.
The plant should be watered when the top 1-2 inches (3-5 centimeters) of the soil has dried out. This equates to watering about once every two weeks or so, but this can vary greatly depending on its environment and temperature.
During the wintertime (or the dry period if you live by the Equator or in arid locations) the cactus should be watered less.
Reducing watering to once a month or so to allow the cactus to enter its dormant phase. This gives the plant time to prepare for a spring growing season.
When springtime arrives slowly increase the amount of water given until it is once every 2 weeks.
If your cactus ever begins to turn mushy, then it is receiving too much water. Stop watering it as often and immediately transplant it into a pot with dry soil and a lot of drainage holes.
If you have questions about watering succulents and cacti, feel free to visit our webpage on A Guide to Succulent Watering.
Soil Requirements:
San Pedro and other Echinopsis cacti prefer well-draining soils that lack nutrients. Soils that hold too much water may stunt the plant’s growth or cause it to rot in the future.
The best types of soil are store-bought cacti or citrus plant mixes. They provide adequate drainage and the proper nutrients that benefit cacti the most.
If your local store doesn’t offer cactus or citrus mix, no need to worry! Cacti mixes can be made by mixing potting soil with perlite, sand, peat moss, or even fine gravel.
As long as the soil is able to drain quickly and isn’t toxic, cacti will thrive in it.
Fertilizing:
San Pedro cacti, and their relatives, do not need fertilizer in order to survive; however, fertilizer can boost growth and promote flowering (although it can be quite rare).
For the best results, use a specialized cactus fertilizer that contains nitrogen, phosphorous, and potassium. Follow the directions and used them as recommended based on the fertilizer purchased.
In general, cacti should be fertilized once a month during the spring in order to promote new growth and hopefully produce flowers during the summer.
Leggy Growth:
Sometimes San Pedro Cacti, and other cacti in general, start to grow thin and unstable branches. This is known as being “leggy”.
This usually occurs when a cactus is not receiving enough light, so it starts to grow long and thin to find more.
The best way to fix the issue is to move the cactus to a brighter location or provide it with artificial light.
Lamps and grow lights are perfect for providing additional light if needed.
However, leggy growth is sometimes a result of too much or too little water. Poor soil also causes thin growth.
Too learn more about leggy cacti and succulents (and how to fix them), visit our webpage:
Sun Spot Nursery – Leggy Succulents
San Pedro Cactus Propagation:
Eventually, a San Pedro cactus will grow large enough to separate into individual plants. If you decide to buy San Pedro cuttings or seeds, this short guide will help you to get them started.
There are two primary ways of propagating these cacti:
- Grow from cuttings
- Sprout from seed
Each method has its own benefits and drawbacks.
Propagation by Cutting:
This is the easiest and most effective way to propagate new San Pedro cactus plants.
Step 1: Creating Calloused Cuttings
Take cuttings from well-established plants and allow them to callous over after cutting.
Place the fresh cuttings in a warm, dry, shady area that does not receive direct light.
Allow the fresh cuttings to sit for at least 2 weeks or up to a month (sometimes more). Note that larger cuttings take longer to fully callous over than smaller cuttings.
Check the cuttings every few days to see if they are ready. They have fully calloused when the spot where the cut was made has completely dried out, looking and feeling like a solid skin.
It is essential to allow the cuttings to callous over before planting to prevent soil bacteria or fungus from directly making contact with the body of the cactus.
Planting fresh cuttings directly into soil may lead to rotting.
Step 2: Planting The Calloused Cuttings
Take the calloused over cuttings and set them into the soil, making sure they are planted 2-3 inches (5-8 centimeters) deep.
Wet the top of the soil with a spray bottle for a few weeks, never allowing the soil to become soaked (there aren’t any roots to absorb the water, but there needs to be some moisture to promote root development).
After about 2-3 weeks, the cutting should begin to develop roots. You can check this quickly by giving the cactus a light tug upwards and testing for resistance.
If the cactus feels heavier or cemented into the soil, then it has started to develop roots. If the cactus pulls straight up or isn’t firm in the ground, it needs more time to grow roots.
Once the plant develops some roots, care for it like a normal San Pedro cactus.
Learn more about propagating the San Pedro cactus at The Succulent Source.
Propagation by Seed:
Although not as common as propagation by cutting, the San Pedro cactus also grows from seed.
Place the seeds just beneath the soil and keep them moist. The temperature must be maintained at around 80°F (27°C) during the day and 70°F (21°C) during the night.
Any deviation in humidity or temperature could prevent the seeds from germinating.
After a month or so the seeds will have developed roots and should sprout from the soil. Keep them moist and in a shaded, but light, area for a few months. Once they are large enough, care for them as adult cacti.