Myrtillocactus Geometrizans Guide: How to Grow & Care for “Blue Candle Cactus”

Guide to Myrtillocactus Geometrizans - everything you will ever need to know! Tips for growing and caring for “Blue Candle Cactus”

If you are looking for a fast-growing cactus that can be the focal point of your indoor or outdoor garden, you should put the Myrtillocactus Geometrizans at the top of your list. This succulent is quite massive, and it has a very interesting shape when it reaches maturity.

Myrtillocactus Geometrizans goes by many names including Blue Torch, Blue Flame, Blue Candle, Bilberry Cactus, or Blue Myrtle Cactus. Unlike most succulents which take years to grow, this cactus is quite a fast grower and in proper conditions, it will reach maturity with minimum effort on your part.

Read on to learn more about growing, watering, planting, and propagating Myrtillocactus Geometrizans.

About the Blue Candle Cactus

  • This succulent belongs to the Myrtillocactus genus, which in Greek means small myrtle. The Geometrizans name comes from the plant’s geometric patterns.
  • This cactus is native to central Mexico, growing in a habitat that exceeds 50,000 square kilometers. It prefers elevations of over 1000 m above sea level, and it can be found predominantly in xerophilous scrub and tropical deciduous forests.
  • This plant bears edible blue fruits which greatly resemble blueberries. The fruits are quite common and are sold under the name of garambullos.
  • Myrtillocactus Geometrizans is also used in medicine. It contains valuable extracts such as Peniocerol and Chichipegenin which are used for treating inflammation. It also contains sterols which are believed to inhibit the growth of colon and breast cancer cells.
  • This cactus is generally not toxic, but it can sometimes cause gastrointestinal ailments in pets, so it is best to keep it out of their reach.
  • While its fruits are edible, the plant itself can be psychoactive. It contains mescaline, one of the strongest hallucinogen substances known to man.
  • Moreover, the Blue Candle cactus can be a hazard outdoors due to its size, so it is best to keep it within a safe distance from children’s playgrounds and pathways.
  • The Blue Candle Cactus does not have any serious disease or pest problems. However, like most cacti, it is susceptible to root rot if it is drowned in water.
Myrtillocactus geometrizans
Myrtillocactus geometrizans

Blue Candle Cactus Features: An Overview

  • The Blue Candle cactus has a columnar shape when it is young, but as it matures, it develops a thick and short trunk, from where multiple stems grow, creating a massive candelabrum shape. It can grow as high as 5 meters and the crown can also reach about 5 meters in diameter.
  • It features multiple stems that are about 10 cm wide, and each stem grows up to 8 ribs. The ribs are 2,5 cm deep with aureoles every 2,5 cm. Each aureole will develop up to 9 spines. The spines are black and smaller than one cm.
  • Considering the size of a mature Blue Candle cactus, you will be surprised to see that its flowers are quite small, growing no bigger than 3,5 cm. They have a creamy green-white or yellow shade. The flowers are tubular and attached to the stem.
  • Blue Candle cacti usually bloom in spring, from February to April, but don’t be surprised if your cacti still have flowers in the middle of the summer. The flowers have an intense fragrance and attract plenty of pollinators.
  • There are several interesting variations to choose from if you want to add some versatility to your garden. For example, the Fukurokuyuzinboku has plump ribs that resemble human breasts, which is why it is also known as the Breast Cactus.
  • The Cristatus variation is also very popular. It features a highly dense tree-like trunk and crested ribs, and it is also known as the Dinosaur Back Plant. This variation can also be variegated, which makes it even more interesting as the bluish epidermis is beautifully contrasted by yellow ribs.

Growing Blue Candle Cactus

While the Blue Candle cactus is quite resilient, it does not handle cold very well. If you live in an area with cold winters, it is best not to grow it outdoor as the first frost may kill it. Even if you place the Blue Candle cactus in a sheltered location, try to keep a constant temperature that does not drop under 10 °C. It thrives in USDA zones 9a to 11b.

As far as sunlight needs go, young plants will require either a partial shade or filtered sunlight. As they mature, their love for sunlight grows, so mature plants will enjoy full sun exposure.

This cactus will enjoy regular feeding during its growing seasons so feel free to fertilize it once a month or once every three weeks. Opt for a fertilizer that has a higher concentration of phosphorus and is low in nitrogen. Cease fertilization during the wintertime, as the plant will go into its dormant phase. If your cactus is potted, place it in a slightly darker area during the cold winter months to encourage its hibernation.

Myrtillocactus Geometrizans – “Blue Torch Cactus”, From Amazon

Planting Blue Candle Cactus

Like most cacti, the Blue Candle Cactus will require soil with good drainage, preferably a cactus and succulent soil mix with plenty of gravel. You can place some pebbles at the bottom of the pot to ensure good drainage and proper air circulation. You can also add gravel around the plant to simulate a rocky environment which is usually native to cacti.

Since this is a fast-growing plant, its roots will quickly outgrow their pots, so it should be repotted once every other year. When repotting, always check the roots for damage and remove any sick or wilted roots.

After repotting your Blue Candle cactus, don’t water it immediately, but allow it about a week to adjust to the new pot. Blue Candle cacti perform best in dry environments so dry soil will make the transition easier.

Watering Blue Candle Cactus

Watering frequency will depend on the climate conditions where this cactus is grown. The watering schedule does not differ from other cacti which means that the Blue Candle cactus prefers not to be bothered until the soil is completely dry. Once the soil is completely dry, it will enjoy a thorough watering session.

It is best to reduce the watering frequency as the weather gets colder. During the wintertime, you should only water your Blue Candle cactus once every couple of weeks, giving it just enough water to prevent its stems from wrinkling.

Unlike other types of succulents, this cactus does not thrive in a humid environment, so avoid misting and try to keep it in a space where humidity levels do not exceed 30%.

Propagating Blue Candle Cactus

This cactus propagates through seeds and stem cuttings. Obviously, it is more time-consuming to propagate through seeds, but it can be more rewarding to see your plant grow from seed, especially since this is a fast-growing cactus.

To propagate from seeds, you will need to allow the fruit of an existing plant to ripen. Clean it well and allow it to fully dry. Gather the seeds and store them until you are ready to plant, preferably in the warm months of spring or summer. Use terracotta or plastic pots and fill them with a gritty compost with good draining properties.

The compost should be slightly moist. Sprinkle your seeds and gently sow them. Next, cover them with a thin layer of vermiculite. Cover the pot with a plastic bag to preserve the moisture and remove the bag after a few weeks when you should see sprouts. During this phase, you won’t have to water the plant. Seedlings don’t need water or nutrients. They just need a warm and humid environment, from which they can extract just the right amount of moisture that they need.

Blue Candle Cactus
Blue Candle Cactus

To propagate from cuttings, use a sharp knife to remove a cutting from a healthy stem. A 10 cm cutting should be enough, and it is best to use a pot that is about half the size of the cutting. You should allow the cutting at least a couple of weeks to dry before attempting to plant it.

Your Blue Candle cactus cutting will be ready for planting when it has developed a callous on the cut area. You can also use a growth hormone on the freshly-cut area to give the new plant a boost of nutrients. Use a mixture of vermicompost, sand, and garden soil. Use your finger to dig a hole that almost touches the bottom of the pot, place the cutting in the hole, and gently tap the compost around it to give it some stability.

Mist the soil at its base and then press around the plant to settle the soil. Allow the new plant a week to adjust to the new pot, give it a slight watering and then leave it in a sunny spot for up to 4 weeks. After this time, it should have some sturdy roots and you will be able to repot it in a bigger pot.

In Conclusion

These desert cacti will add an exotic touch to any space, whether you choose to grow them indoors or outdoors. They are quite sturdy and do not need a lot of care, provided that are grown in a suitable environment similar to their native habitat.

The Blue Candle cactus is suitable for xeriscaping and rock gardens. Due to its unique shape and color, it will be the focal point of an all-cacti garden, and it will also look great among flowering perennials and various types of shrubs.

Indoors, Blue Candle cacti will grow fast in any well-lit room, and they won’t be any trouble, not even for a beginner gardener. To keep a Blue Candle cactus alive and happy, avoid overwatering it, keep it in a room with moderately warm temperatures, and try your best to keep it away from drafts.

Ready to grow Myrtillocactus Geometrizans? Share your thoughts and questions in the comments below!

Miruna is an experienced content writer with a passion for gardening. She is the proud owner of an outdoor rose garden and an indoor collection of tiny succulents. She bought her first succulent 10 years ago - an adorable Echeveria Setosa. Now she owns more than 100 succulents and cacti of different colors, shapes, and sizes. Miruna is a versatile writer and, as you might have guessed, her favorite topic is gardening. Contact

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