The Blue Torch Cactus ‘Pilosocereus Pachycladus’

The Beautiful Blue Cacti—Pilosocereus

Did you know that cacti can be bright blue? Yup, that’s right—those photos you’ve seen on Instagram of blue cacti are not fake nor photoshopped! A genus of columnar cacti called Pilosocereus is so vibrant and blue that you almost won’t believe they’re real. They often have contrasting orange spines, making them look even more beautiful and unreal!

Even though most Pilosocereus cacti have an otherworldly color, they’re not rare or hard to track down. Species like Pilosocereus pachycladus are widely cultivated, so you may even be able to find one at your local garden center!

Like all cacti, Pilosocereus love to soak up the sun and hate the cold. Keep reading if you want to learn more about where these great cacti came from and how to care for them in your garden!

pilosocereus azureus
Pilosocereus azureus @Pinterest

Origins Of Pilosocereus Pachycladus

Pilosocereus is a genus of tall columnar cacti found in warm areas of the world like Mexico, Brazil, and the Caribbean. There are about 50 different species of cacti in this genus, and although not all of them are that vibrant bright blue color we love, many of them are!

Many species of Pilosocereus also have white wool covering them, which is how the whole genus got its name. Pilosocereus roughly translates to “hairy candle” in Latin. It’s probably one of the funniest plant names we’ve ever come across, but it makes sense! These blue cacti have a columnar shape that resembles a candlestick, and they are pretty hairy because of all that white wool! 

Two other things that make these blue cacti unique are their beautifully colored spines and flowers. Many of them have bright orange spines and vibrant blue flowers that match their beautiful blue stems. These are some of the most colorful cacti we’ve ever seen, so they’re a great way to inject a little color into your garden! 

One more thing to note about Pilosocereus is that they can get to be tall. Some species reach 32 feet before they’re done growing! Because of how tall they get, most succulent gardeners plant them outdoors in the ground instead of keeping them in pots inside. They also tend to do better outdoors because they need so much direct sunlight, so that’s something to keep in mind. 

The Beautiful Blue Cacti—Pilosocereus
Bright orange spines @trexplants

How To Care For The ‘Blue Torch Cactus’ Pilosocereus

You’re probably dying to get your hands on one of these bright blue beauties so you can plant the cactus in your garden. But first, you’ll have to learn how to care for it! Keep reading to find out what you need to do to keep the newest addition to your succulent collection happy and healthy.

Water and Soil Requirements

Pilosocereus can handle more water than other succulents and cacti, especially in the summer, but you still have to be careful not to overwater them! Their roots will start to rot if they sit in too much water or soil that doesn’t drain well. That’s why it’s essential to use cactus soil with lots of gritty ingredients. We like this one because it has perlite, sand, and limestone, which all promote drainage and help the ground dry out faster. 

Pilosocereus are pretty thirsty cacti! Some gardeners report that they need water almost daily during the warmer months. We recommend watering your Pilosocereus plant about once a week for most of the year. We then watch it closely in the summer and give the plant more water.

Before giving your cactus a drink, always remember to test the soil first. This helps prevent overwatering and root rot. Stick your finger or a moisture tester in the ground. Do this about once a week during the colder months and once a day when it’s warm outside. If the soil is dry a few inches down, give your cactus some water. If not, wait to water the cactus and recheck the ground later. 


The Beautiful Blue Cacti—Pilosocereus
Pilosocereus are pretty thirsty cacti! @charleen_aiden

Temperature and light requirements for Pilosocereus Cacti

Pilosocereus are from hot countries like Brazil and Mexico, so they love warm weather and full sun! They grow best in tropical temperatures of 70 degrees or higher and need lots and lots of bright, direct sunlight. Don’t be afraid to put them in full sun, even during summer. In Brazil, Pilosocereus grows in full sun in temperatures as high as 125 degrees, so you likely won’t have to worry about sunburn with this cactus-like other succulents. 

One thing you do have to worry about when growing Pilosocereus is frost. In their native environments, they don’t face temperatures lower than 50 degrees. If there’s a cold snap, your cactus may get damaged. So make sure you take measures to protect your cactus by using a frost cloth when the temperature dips. And of course, don’t try to grow a Pilosocereus if you live somewhere that gets lots of snow and ice! 

The Beautiful Blue Cacti—Pilosocereus
Top view of the Pilosocereus cacti @jacquelinetaylor9611

Fertilizer Requirements for Pilosocereus Cacti

Pilosocereus cacti are fast-growing, but fertilizing them can help them grow even faster! They grow fastest in the summer, so that’s the best time to fertilize them. Use a water-soluble, balanced fertilizer, like this one, up to once a month during the summer. 

Before applying fertilizer to your growing cactus, dilute it to half strength so it doesn’t burn your plant. If the package says to use a tablespoon for each gallon of water, use a half tablespoon instead.  

There you have it! Those are our best tips for keeping your Pilosocereus cactus happy and healthy.

Now that you know more about them, will you get one of these great blue cacti Pilosocereus for your garden? Let us know in the comments section below! Happy planting! 

The Beautiful Blue Cacti—Pilosocereus
Blue cacti Pilosocereus @florariym40

We believe this cactus will add a gorgeous pop of color to your garden. We wish we had known about them years ago!

Are you already growing a Pilosocereus (or 2)? Drop a comment below on some care tips you’ve experienced with your cactus! And share your photos in our exclusive Facebook group, Succulent City Plant Lounge!

Looking to add some additional cacti to your garden? Check these cacti out with our articles in The Soft Monkey Tail Cactus, The Rat Tail Cactus: Everything You Need to Know, Everything You Didn’t Know About the Star Cactus, or 9 Rare Cacti That’s Hard to Find!

I loved learning about these cacti and am now inspired to add more to your collection?! (We don’t blame you). Check out Succulent City’s new ebooks covering topics from “All the Types of Succulents for Indoor and Outdoor,” “Different Types of Planters,” and many more helpful in-depth ebooks. Head to this link to view our full line of ebooks and get started with our complimentary guide.

Happy planting!


Richard Miller

Salute everyone. It's Richard, the author of this Succulent & Xeriscaping blog. I am a traveler and a nature lover looking for a connection with the wild green. In my journey, I found a love for succulents and xeriscaping. What attracts me is the long-lasting & unique beauty of every plant I have the chance to see with my own eyes. Welcome to my little blog and let's enjoy a good time together!

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6 thoughts on “The Blue Torch Cactus ‘Pilosocereus Pachycladus’

  1. Hello! Great article! I have two blue torches and am debating potting them up. Do they grow faster in larger pots? Also, do they have a preference on being potted alone or together? Thank you!

  2. Our pilosocereus has been frost burned and we are not sure what to do. If cut down, will it regenerate? The plant has two legs, and there is a small “pup” coming off the bottom of one leg that looks nice and healthy, but the two 6 foot legs are partially browned from a bad frost. We want to save the plant and get t looking healthy again. Please feel free to email me with any advice! Thank you.

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Posted in Cacti