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The fairy castle cactus is a night-blooming cactus named for its resemblance to the turrets of a castle.



What Is a Fairy Castle Cactus?

The fairy castle cactus––also known by its scientific name Acanthocereus tetragonus––is a slow grower that can reach up to six feet tall. Other common names include night-blooming cereus, triangle cactus, and barbed-wire cactus. This columnar cactus plant is native to Central America, Mexico, northern South America, the Caribbean, and the southern United States. While the fairy castle cactus rarely blooms, it will sometimes produce large white or yellow flowers.

How to Grow and Care for a Fairy Castle Cactus

The fairy castle cactus is a low-maintenance, slow-growing plant that is a good plant for inexperienced gardeners. Follow these tips to maintain a fairy castle cactus indoors or in your garden:

  • Ensure the fairy castle cactus receives plenty of light. Fairy castle cacti kept as house plants should be grown in a space that receives lots of sunlight. If these plants do not receive enough light, the colors will fade and their columns will become misshapen. This is a full-sun plant, but it will survive in partial shade.
  • Water the fairy castle cactus sparingly. To avoid overwatering your fairy castle cactus, allow the cactus potting soil to become dry between waterings. Standing water or soggy soil will cause root rot or attract mealybugs, which will likely result in your cactus perishing.
  • Regulate the temperature of the plant’s environment. As long as it receives sufficient water, the fairy castle cactus thrives in hot weather. However, it is highly sensitive to frost and should be brought indoors if the temperature outdoors reaches below 32 degrees Fahrenheit. Carefully consider the indoor placement of your cactus as well, as cold drafts or air conditioning can be damaging.
  • Plant the fairy castle cactus in well-draining soil. As with many other cacti species, the fairy castle cactus requires well-draining soil. Using soil with large percentages of gravel, bark, sand, or perlite will help ensure that soil does not become soggy.
  • Use an unglazed pot with drainage holes. A terra cotta pot can help absorb excess moisture.
  • Add fertilizers and plant food to encourage growth. In warmer months, plant food can be added to the soil or water to encourage growth, but it should not be used when the cactus is dormant in the winter. In the spring, fertilize with cactus fertilizer as growth resumes.
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How to Propagate a Fairy Castle Cactus

Fairy castle cactus propagation is relatively easy. To grow new plants from a fairy castle cactus cutting, follow these steps:

  1. Sever a branch. Using a sterile knife or scissors, cut off a branch at the base. Sterilization of your cutting tool will prevent your cactus from developing an infection.
  2. Dry out the cutting. Before replanting, allow the severed end of the branch to dry out and harden to encourage the new cactus to form roots.
  3. Plant the cutting in an unglazed pot with drainage. Overwatering will damage fairy castle cacti, so be sure to plant your cactus in an unglazed clay pot with drainage holes so that excess moisture is able to evaporate.

Learn More

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