How to Propagate Dying Fairy Castle Cactus

How to Propagate Dying Fairy Castle Cactus

A year ago I bought a cactus from an online store because I liked it. The cactus is starting to turn brown so it doesn’t look as good. A friend said it might be root rot from poor drainage, and another said it might be that the cactus has gotten too big for its pot. 

When I first got my fairy castle cactus it looked fine, but then it slowly started to decline. Now, the top is brown and a few of the leaves have just fallen off. I’m worried that if I don’t do anything it will die.

So, I decided to do some research on other blogs, articles, and forums and came across some great information on how to try to get my cactus back into healthy condition!

First, I had to figure out if my cactus actually was suffering from root rot or over-watering. According to this website, here are the symptoms of root rot:

  • Brown, dead lower leaves.
  • Leaves with brown edges.
  • Softening of the stem.
  • Wilting of lower leaves or stems.

I noticed that all of these symptoms were true for my plant but I also noticed that there wasn’t any softening or wilting of the stem.

Acanthocereus Tetragonus

A fairy castle cactus is an interesting type of cactus that resembles a castle. It can be found in different colors and it looks like a miniature castle. Its color can be brown, yellow, green, or red.

The branches clump together as they grow vertically and form what appear to be the turrets in the castle. This is why it is known as “fairy castle cactus”. The other terms for the plant include “triangle cactus”, “barbed wire cactus” and “Chaco”.

The 5-sided stem gives it the look of a castle tower. Fairy castle cactuses are not difficult to take care of at all. They grow in full sun and need very little water to survive. You want to keep the soil dry, but not bone dry. Fairy castle cactuses should be watered only when the soil has dried out.

It is a type of succulent that hardly blooms. If it does, it will have white or yellow flowers in summer.

Those who want to grow the miniature cactus indoors should know that it can reach a height of 1.8 m (6′).

Acanthocereus tetragonus is native to Florida and the Lower Rio Grande Valley of Texas, Mexico, Central America, the Caribbean, and northern South America, and belongs to the Cactaceae family.

General information:

Also known as Fairy Castle Cactus, Triangle Cactus, Barbed Wire Cactus, and Chaco.

Plant family: Cactaceae

Origin: Florida and the lower Rio Grande Valley of Texas, Mexico, Central America, the Caribbean, and northern South America.

Height: 1.8m (6′)

Exposure: Total or partial sun for up to 6 hours.

The requirements for the water: The method of soak-and-dry is suggested, where the soil is watered thoroughly only when it’s certified dry.

Soil Type: The soil is well-drained and aerated such as the standard potting mix or cactus mix that includes additional ingredients such as perlite, pumice, gravel, and sand, to aid in drainage.

soil pH: 6,0 a 7,5

Why Is My Acanthocereus Tetragonus Dying?

If your Acanthocereus tetragonus is dying, the main suspect is overwatering. The other possibility could be that the Fairy Castle cactus has been infested by disease-causing pests.

The Fairy Castle cactus requires very little water. It should be watered when it appears to be dry, and not before or after.

Here are some reasons why your Acanthocereus tetragonus could be dying:

– There is too much water in the soil.

– The Fairy Castle cactus has been infested by a disease-causing pest.

– It’s not getting enough light.

Excessive Watering

The most common mistake people make is giving their plants too much water. Overwatering causes the root cells to fill with so much water that they rupture, which is why you only want to water the soil when it’s 100% dry.

When you notice discoloration, immediately cut these parts off with a sharp, sterilized knife or garden shears.

Next, pull the plant out of the ground so you can examine its roots. If you notice any black spots on the roots or they seem thin and weak, some of your soil may have become compacted by overwatering.

Use a trowel to loosen the soil around each plant and adjust its positioning so there is better drainage around it.

If you find that the roots are covered in white and grey fungus but are still firm, simply scrape it off with a sharp and sterilized knife or garden shears.

If they’re mushy or there’s a lot of fungi. You’ll want to do this carefully so as not to damage the plant’s roots or harm yourself in any way. Use a tool that’s sharp and clean—you don’t want to accidentally spread any fungal spores while doing this.

Keep yourself safe by wearing gloves, too. If you have a hard time getting the fungus off with your tools, try soaking overnight in a 1:1 mixture of water and hydrogen peroxide (it is available for sale here) (the fungus will die in this solution).

Pest Infestation

Insects like mealybugs, spider mites, mealybugs, and aphids are found in the succulents of Acanthocereus Tetragonus in order to consume their sap. Once the plant has run out of sap, the plant starts to shrink and weaken slowly.

They also produce white, cotton-like substances on the leaves, which could be the cause of fungal infections.

To keep pests out from the Triangle Cactus spray it with Neem oil (buy on amazon). It is possible to eliminate the pests off the plant by wiping it clean with an absorbent cotton ball, immersed in 70% isopropyl alcohol (it is for sale here), or disinfectant soap.

How to grow and care for Acanthocereus Tetragonus

The Fairy Castle Cactus can be part of a novice horticulturist’s “starter kit” as it is easy to grow and care for. If you are just starting out with indoor gardening or are looking for an alternative houseplant, then this cactus would be a good choice. You may have seen them in gift shops before so you know that they last pretty long and aren’t picky about lighting or watering.

The Fairy Castle Cactus is one of the most purchased succulent plants for the interior. It is resistant to changes in weather conditions and durable enough that you don’t have to spend too much time looking after it.

The Acanthocereus tetragonus, or as it is commonly known, the Fairy Castle Cactus, is a delightful little plant with character. It is a fairly hardy plant that is an ideal choice for those of us who want to grow our own succulent plants without spending too much time weeding, cutting back dead material, and other upkeep. If you’re looking for an easy-to-grow indoor cactus, consider the Fairy Castle Cactus.


Acanthocereus Tetragonus requires regular exposure to light. If you wish to plant Triangle Cactus outdoors, plant it in a location that will get up to 6 hours of full sun.

The Fairy Castle cactus goes dormant during winter. It does not require as much sun.

While it’s a sturdy succulent Acanthocereus Tetragonus doesn’t seem to be difficult to grow or cold. It is best to plant succulents in a pot that can be brought indoors in the event of temperatures dropping below 30 degrees Fahrenheit (-1.1degC).

As a succulent for indoor use plant put the miniature cactus next to the window that gets up to 6 hours of total or partial daylight each day.


Typical of the succulent plants of this family, the best way to water the Acanthocereus tetragonus is when it has been verified that the soil is completely dry. There are two ways to do it.

First of all, if the soil feels dry to the touch, it is a sign that it needs water. Second, a more accurate method would be to insert a stick 1 to 2 inches into the ground. If the end of the stick feels dry, then it is ready to be watered.

There are two rules to keep in mind when watering plants:

  • Water the ground and not from above. Watering the plant directly will retain moisture for longer. If the succulent has a fungal disease, the water could spread it to other plants.
  • Always soak the soil well. If the plant is in a pot, you’ll know you’ve thoroughly soaked it if excess water starts to come out of the drainage hole.

Pot and Soil

Select a pot that allows adequate evaporation of water from the soil. The ideal pot for Acanthocereus tetragonus is terracotta or ceramic. Never use plastic pots because they will retain too much moisture and this will rot the roots of your plant.

Another important factor in choosing a good pot for growing any cactus is size. It should be large enough for the plant to fully grown and be stable.

Make sure there is good drainage. Water should drain easily from underneath the pot. If you notice water accumulating at the bottom of your pot for more than one hour after watering, then you should repot your plant into a larger container that allows faster drainage.

The barbed wire cactus is known for being a hardy succulent that can grow even in poor-quality soil.

To ensure the highest expansion and longevity, choose an aerated, well-drained soil for this cactus. Add ingredients such as standard pots or cacti that have additional ingredients such as pumice, perlite, gravel, and sand for better drainage.

Propagation of  Acanthocereus Tetragonus

Acanthocereus tetragonus is a cactus with an interesting appearance. It grows as a deep green rosette of columnar stems which can reach up to 8 feet tall. The stems are furrowed with sharp spines which come in shades of yellow and red.

One way to propagate Acanthocereus Tetragonus is through cuttings. Cut off a stem from the base at an angle, making sure to include a few centimeters of the thick central stem.

Next, you can begin propagating by seed. The seeds are very small and black, but you need only one for it to grow into a plant that will produce thousands more seeds in its lifetime.

Method 1: Cuttings

Step 1: Cut a healthy stem from the main plant using sharp, sterilized garden shears.

Step 2: Place the cuttings in a dry place for 2-3 days so they can develop hard calluses.

Step 3: When the cuttings have become calloused, plant them in soil that drains well.

Step 4: Keep the soil slightly moist by misting it every day until the roots have taken hold.

Step 5: Once the cuttings have taken root in the soil, you only need to water them when the soil is 100% dry.

Method 2: Seedlings

Step 1: Buy good-quality seeds from a reputable garden store.

Step 2: Plant the seeds in soil that drain well.

Step 3: Mist the soil to keep it slightly moist.

Step 4: Place a plastic cover over the seeds and place the pot near an area that receives indirect or partial sunlight. This will start the germination process.

Step 5: When you see the seeds sprout, remove the plastic cover. Water the soil when it is completely dry.

Frequent questions

Is Acanthocereus Tetragonus Toxic to Cats and Dogs?

Acanthocereus tetragonus is not listed on the list of toxic plants for dogs and cats by the American Society for the Prevention of Cruelty to Animals (ASPCA ).

This plant contains grayanotoxins which can cause vomiting, diarrhea, depression (lethargy), lack of appetite, difficulty breathing, muscle tremors, and seizures in dogs. The toxicity level will vary depending on the amount consumed by your dog or cat.

Does Acanthocereus Tetragonus Produce Flowers?

Acanthocereus tetragonus barely blooms. But when it does, it will produce white or yellow flowers in summer.

Anwar Hossain

My name is Anwar Hossain. I am a cactus lover, researcher, and cactus blogger.

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