Why Is My Fairy Castle Cactus Turning Brown? 

Why Is My Fairy Castle Cactus Turning Brown? 

Imagine your cactus looking like this: … and then, one day, it starts to look like this: What happened? Did your fairy castle cactus turn brown overnight? Or was it a slow process? Why did it happen? Is it going to die? What do you do to fix it? Today we are going to find out the answers so that you never have to be surprised by a brown cactus again.

Why Is My Fairy Castle Cactus Turning Brown?

As much as we all love the look of a cactus, it’s not always easy to properly take care of them. One of the most common problems with cacti is that they turn brown and shrivel up when they’re not taken care of properly. This can be annoying because it ruins the aesthetic you worked so hard to set in place and can even lead to you having to throw out the plant, but there are several reasons why this happens and many ways to avoid it.

Corking – Signs Of Aging

Corking is when the bottom parts of the oldest stems on a fairy castle cactus start to turn brown and feel woody.

 It looks like a sign of sickness, but it’s actually part of the natural aging process. While it’s unattractive, it actually helps support the cactus as it grows taller.

Corking is a natural aging process that happens to some cacti. As they grow, the very bottom parts of their oldest stems will begin to look like wood: brown and scaly. You may think this looks sickly, but it’s actually a sign that they’re in good health! It’s called corking, and it’s actually a great sign that your plant is growing nicely.

Root Rot

Root rot is a common problem for cacti, especially fairy castle cacti, which are less able to tolerate being overwatered than other types of cacti. If the bottom part of the plant starts turning brown and feels squishy, the plant has probably begun to succumb to root rot.

Root rot actually isn’t that hard to avoid; you just have to make sure not to water your fairy castle cactus too much! The best rule of thumb is to only water it when the soil it’s in is completely dry to the touch.

If you do notice root rot setting in, stop watering the plant and repot it in well-drained soil. Then cut off any rotted parts of the plant.

It’s important not to overwater your fairy castle cactus in general, but if you follow this rule you should be able to keep root rot from becoming a problem for your plants!

Damage From Sunburn

If you’ve ever heard the warning, “Don’t leave your cacti out in the sun too long!” you might be surprised to learn that the same sun that helps your cactus grow can also damage its delicate tissue. The tops of the cactus will look droopy and dull, turning yellow, white, or brownish if they have been getting too much sunlight, and like a sunburn, their skin will peel off. This means it’s time for a little shade and some tender loving care.

If you’re growing your cactus indoors, try to place it next to a window that gets direct sunlight for about that amount of time each day. If this isn’t possible and you don’t have a way to restrict the exposure of your plant to the sun, consider getting a shade for your plant or placing it on an east-facing windowsill instead.

If you’re growing your cactus outdoors, place it strategically so it won’t be under the blazing sun all day long. If that isn’t possible either, consider getting a shade for your plant to protect it from the direct rays of the sun.

Fairy castle cacti love bright sunlight, but they only need it for about six hours per day.

Sudden Environmental Changes

Shockingly, fairy castle cacti can be burned by a prolonged exposure to direct sunlight, causing the edges of their leaves to turn brown and crispy. Remove the burnt edges with a sharp knife to prevent any further damage to the plant and take steps to avoid this problem in the future.

The biggest environmental change you can make is moving your fairy castle cactus from a shady spot to full sun. If it’s used to getting mostly shade and you suddenly move it into 6 hours of strong daily sun, there’s a good chance it will experience sunburn because it won’t have had a chance to adapt to its new environment.

If you think your fairy castle cactus has been starved of sunlight, begin by positioning it in partial shade and then slowly introduce it to additional sunlight until it’s fully acclimatized to the extra rays and higher temperatures.

Begin by exposing your cactus to the less-intense morning sun, and slowly expose it to more intense afternoon sunlight. Once your cactus is accustomed to all that light and heat, you might be able to leave it outside year-round if you live in a warm climate like southern California or Florida.

Bug Problems

If you’re a cactus lover like me, you probably thought that you were safe from insects—the hard, waxy surface of a cactus is not exactly inviting to bugs. So imagine my surprise when I found a few small bugs crawling around on one of my plants!

It turns out that there are actually lots of bugs that love eating cacti (who knew?), and if they get a foothold in your plant, they can cause all sorts of problems for your plant. Once a bug gets into the plant itself, it can cause brown, squishy spots to appear on the plant’s green surface. If the plant is infested enough, it will eventually die!

If you find this happening to your fairy castle cactus, don’t panic—there are still things that you can do. The first thing you should do is take some tweezers and pick off any bugs you see on the surface of the plant. If they’re gone, then great! If they come back, though, then you may have another problem.

One thing you could try is taking the cactus outside and blasting it with a hose. This might kill any bugs that are hiding inside the spines or under the soil.

How To Stop Your Fairy Castle Cactus From Turning Brown

The way you care for your fairy castle cactus and the environment around it can affect how healthy your plant looks. In order to keep your cactus from getting brown spots, here are some things you need to do:

-Make sure to water it when the soil is dry.

-Avoid letting the roots go dry.

-Move your fairy castle cactus to a well-lit area.

-Try not to move it around too much.

-Be careful where you place the cactus in terms of temperature and humidity.

-Keep an eye out for pests that could be affecting the plant’s health.

Acanthocereus tetragonus “fairy castle”

Acanthocereus tetragonus “fairy castle” is a variety of the species Acanthocereus tetragonus , very popular as an ornamental plant all over the world. This variety is characterized by being a very branched columnar cactus that only reaches a little over 70 cm in height.

The trunk always green; it can be light green when exposed to a strong light source, or darker when the lighting is low. It has 5 very conspicuous angles with numerous areolas on the edge of these. Each areole contains numerous central yellow spines and small white radial spines.

The frequent ramifications in this cactus appear in the areoles. Each areola can generate a new trunk and thanks to this, a large central stem with numerous smaller branches on each side can be observed; these ramifications give the appearance of a small castle with side towers (hence its popular name).

Some Necessary Tips for Fairy Castle Cactus


It needs places with intense light but never exposed to the summer sun; in mild winters it can be exposed without problems throughout the day. It also adapts to indoor cultivation with fairly powerful artificial lighting sources.

Room temperature:

It needs temperatures above 15°C for optimal growth. Temperatures below 10°C for long periods cause stem and root rot.


The substratum for this species should be very permeable, or else the cactus will rot. It does not have any specific requirements for substrate, but it needs to be loose and well-draining.

Irrigation frequency:

Water only when the substrate is dry. In winter we must water once every fifteen days.

Plagues and diseases:

It is very resistant to almost all types of pests but can be frequently attacked by mealybugs. The most frequent damages are associated with low temperatures and waterlogging in the substrate.

Anwar Hossain

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

Recent Posts