Fairy Castle Cactus
Acanthocereus tetragonus
The Fairy Castle Cactus (Acanthocereus tetragonus ‘Fairy Castle’) is a popular ornamental cactus known for its whimsical structure of stacked, column-like arms that resemble the turrets of a miniature castle. This slow-growing cultivar is native to the Americas and is often chosen for its unique, architectural form.
Each stem is ribbed and may produce small spines along the ridges, though they’re typically less intimidating than those of larger cacti. It’s a fantastic starter cactus that requires very little care — just lots of light and dry soil.
While flowering is rare indoors, mature plants can produce small white or yellow blooms at the tips of their stems when grown in ideal conditions.
Quick Info
- Light: Bright
- Water: Low
- Size: Up to 2 feet tall
- Humidity: Low
- Temp: 60–85°F (15–29°C)
- Flowering: Yes
- Type: Cactus
- Dog Safe: No
- Cat Safe: No
- Kid Safe: Yes
Toxicity Info
- Dog Safe: No
- Cat Safe: No
- Kid Safe: Yes
Notes for Pets: No – Mildly toxic and spiny
Care Instructions
- Place in a bright location with plenty of direct or filtered sunlight
- Use well-draining cactus/succulent soil and a pot with drainage holes
- Water deeply but infrequently — every 3–4 weeks depending on season
- Avoid misting or humid environments
- Rotate occasionally for even growth
Common Problems
- Soft or drooping stems: Overwatering or poor drainage
- Shriveled stems: Underwatering or extreme heat
- No growth: Normal for winter dormancy; it’s a slow grower year-round
FAQs
It can bloom when mature, but this is rare indoors. Outdoor plants in warm climates may produce flowers after many years.
Yes — cut a small “tower,” let it callous over, then plant it in dry soil.
It has small but sharp spines, so handle with care or use gloves.
Related Plants
Barrel Cactus
A round, spiny cactus with golden ribs and a striking sculptural look — the Barrel Cactus is a low-maintenance desert beauty perfect for sunny spots.
Star Cactus
A small, spineless cactus with a perfectly round, star-shaped form — the Star Cactus is a rare, easy-care collector’s plant that thrives in bright, sunny spaces.