How to Grow a Crested San Pedro

The Crested San Pedro is a unique, rare, and stunning variation of san pedro cactus with curvy waves that make them highly sought after in the cactus community. In this guide, we’re going to go over why cresting happens and how to take care of your own crested San Pedro Cactus. 

What is Cresting?

Cresting, also known as fasciation, in cacti occurs when the growing point of the plant, called the apical meristem, becomes elongated or flattened instead of producing a typical round, columnar growth. The classic shape most commonly exhibited by the Pachanoi crest looks like a fan-like structure, with wavy, curving folds. Then, you see others that aren’t as folded, featuring more elongated, linear, or pitchfork-like growth patterns.There are also ripple or wave crests that undulate and turn all around itself tightly like a brain. 

Why Does Cresting Happen in Cacti?

There are a few theories as to why cacti started to crest but it boils down to two main things: genetics and viruses.

Genetic Mutations

Mutations occur when the genetics of a cactus are naturally altered, causing the growth pattern to change. This also means the cresting pattern could be passed down when hybridized with another cactus.

Infections

Another cause of cresting is infections. Some bacterial or viral infections can disrupt the normal cellular processes of cacti, leading to unusual growth patterns, including cresting.

Physical Damage

While some people commonly attribute physical damage to the tip as a source of cresting, this is only slightly true. Based on our experience with Trichocereus, physical damage can trigger cresting ONLY if cresting is present in the genetics of the cactus.

Reversion to Columnar Growth

Sometimes crested growth forms can revert back to normal columnar growth in its normal life cycle or from environmental changes. If a crested San Pedro experiences significant etiolation, or the plant undergoes stress or damage, it may revert to a more stable columnar growth pattern. But don’t stress; reverting is normal and happens. Our recommendation is to keep the reverted section on until the next growing season to see if it will crest again before removing it if you are inclined to do so. Sometimes a growth pattern of a cactus involves cresting and reversion, and we like to just let the plant do its thing. Enjoy it for what it is!

Lighting & Placement for Healthy Growth

Provide as much light as possible while avoiding sunburn in the peak of summer by using a shade cloth if in full sun. If you’re introducing this cactus to more light from lower light conditions then do so gradually, and if growing indoors you will need to have a high intensity grow light to avoid etiolation. Too little light will cause the cactus to stretch out with thin growth and spaced out areoles, and may cause reversion to columnar growth.

Soil Mix & Repotting Guide

A good time to repot a crested san pedro is when the body of this plant is getting larger and pushing up against the pot. For crested San Pedro, we recommend a well-draining soil mixture that is a ratio of about at least 50% inorganic material like pumice to organic material like peat moss or coco coir, to prevent issues due to too much moisture. If you’re planting a crest outdoors then make sure to amend the mixture to improve drainage for the wet months.

Take your crested cactus and repot as normal, making sure to anchor the cactus well as they can be quite top heavy. You may consider top dressings to help with this.

How/When to Water Crested Cacti

Ensure that the soil is completely dry before watering your cactus thoroughly in the growing season. Crested san pedro go dormant in the winter, so only water when the cactus looks wrinkled or shriveled, as this will help avoid issues due to overwatering.

Ideal Temperature & Humidity

Crested San Pedro’s growing season is from spring to fall, and they go dormant in the winter. They prefer a midrange climate, ideally around 75-85 degrees with about 65% humidity. When temperatures rise above 95°F (35°C), provide shade to avoid heat stress and prevent sunburn, and when temperatures drop below 30°F (-1°C), bring them indoors or use frost blankets to protect against frost damage. 

While San Pedro cacti are tolerant of different humidities they will have more issues in high humidity climates, and typically start to show small brown spots. Larger brown spots indicate more serious fungal issues both likely due to too much moisture or humidity in soil / environment. To help combat & prevent this you can amend your soil mixture to be more inorganic (70/30) and try to improve airflow around the cactus. 

Common Pests

Crested san pedro are more prone to pests than columnar cacti, as the shape of these cacti create more nooks and crannies where pests might hide or go unnoticed. This makes it important to regularly inspect them. A very common pest for crested san pedro are scale and  mealybugs, and if you see signs of ants, then there are most likely mealybugs close-by. They appear as small, white, cottony masses and will hide in the crevices of the crest. 70%+ isopropyl alcohol can be used to treat affected areas from most pests, and as a preventative treatment.

How to Propagate Crested San Pedro

Propagating crested san pedro requires more careful consideration when taking stem cuttings. Take a clean cutting tool and take a section from a crested cactus, making sure to leave a decent portion of the crest on the main plant to continue its crested growth. If you cut too much away then the crested growth may not be able to continue, and columnar offsets may appear.

Allow the cut section to callus over by placing it in a clean, dry location for at least several days. After the cutting has been callused, plant it in well-draining soil and then place it in a spot with bright light. As roots are established you may gradually increase watering frequency.

Crests can also be produced by cross pollination! Not all of the seedlings will come out crested but they will have an increased probability for cresting and mutations.

Fertilization Tips

We recommend a liquid fertilizer with a balanced ratio of macronutrients, to be mixed in every other watering during the growing season.

Crested San Pedro Blooms

When they bloom, crested san pedro will produce impressive, white, night-blooming flowers with black to brown hairs on the outside. Blooming usually occurs during the warmer months of the growing season, from early summer to early fall. Feel free to cross-pollinate from these flowers!

Conclusion

In Summary, crested san pedro cacti are gorgeous wavy plants that owe their unique shapes to genetic mutations or infections. They require bright light, well-draining soil, and protection from extreme temperatures to thrive. Their distinct shape makes them more susceptible to pests, so regular inspections and careful maintenance are essential to keep your cactus healthy and thriving.

Key Takeaways

• Crested San Pedro cacti exhibit rare, wavy, fan-like growth patterns due to a phenomenon called cresting, or fasciation.
• Cresting can occur due to genetic mutations, viral or bacterial infections, and physical damage.
• Crested cacti may sometimes revert to normal columnar growth due to stress or environmental changes. This is normal.
• Provide bright light, while avoiding direct summer sun to prevent sunburn. Indoor growers need high-intensity grow lights.
• Use a well-draining soil mixture with at least 50% inorganic material like pumice.
• Only water when the soil is completely dry; reduce watering during the cactus's dormant winter phase.
• Ideal growing temperatures are around 75-85°F and around 65%humidity. Protect the plant from frost and extreme heat.
• Crested San Pedro is more susceptible to pests, especially mealybugs and scale. Inspect regularly and treat infestations with isopropyl alcohol.
• Propagating crested San Pedro requires careful stem cuttings. It's important to leave part of the crest on the mother plant for continued crested growth.
• Crested San Pedro cacti produce white, night-blooming flowers, which can be cross-pollinated to increase the likelihood of cresting in new seedlings.