Why Is My Fairy Castle Cactus Turning Yellow

Why Is My Fairy Castle Cactus Turning Yellow

The fairy cactus turns yellow following an excess of water, a lack of sun, or the presence of parasites. The fairy cactus does not need a lot of water, and overwatering leads to anoxia and root rot. In general, it should only be watered when the soil is completely dry.

The most common issue with fairy cacti is yellowing or browning leaves or stems. There are two main reasons for this change in color:

-Overwatering your fairy cactus.

-Being exposed to too much sunlight.

If your fairy cactus’ leaves turn yellow or brown, it probably needs more water. The fairy cactus does not need a lot of water, and overwatering leads to anoxia and root rot.

If you want to know how much water your plant needs, stick your finger an inch into the soil. If the soil feels dry, it is time to water your plant.

On the other hand, if the soil feels moist, do not water your plant yet. When you do end up watering your plant, let the water flow through until the excess drains out of the bottom of the pot before replacing the cap on top.  

Do not forget to empty the water remaining in the tank. You can increase the sunlight, but avoid direct exposure as it may cause sunburn.

If the plant is attacked by a small number of pests, eliminate them with alcohol. In case of heavy infestation, spray a pesticide.

Required Condition to Stop Fairy Castle from Turning Yellow

Water and Hardiness

The fairy cactus is present in tropical, subtropical, and semi-desert regions characterized by low rainfall, intense sunshine, and high temperatures. 

It needs to be between 20 and 35 degrees Celsius for optimal growth. It should not be lower than 10, or higher than 35 degrees, and it will slow down and go dormant. It is important that the air humidity does not exceed 10% and that the area be well ventilated.

“Avoid high humidity and water accumulation.”


Fairy Cactus is a sun-loving plant, its care is relatively easy to follow. It doesn’t demand so much attention, but it needs to be exposed to both natural and artificial lighting. This is what will ensure good health and a long lifespan to it.

It can be placed either on an outdoor balcony or in a sunny garden.

You should not expose it to the summer sun for too long.

To prevent high temperatures from damaging your device, it is essential to keep it in shade or to cool it down a bit.


Fairy cactus thrives in fertile and gravel-rich soil with a pH of 6-7.

The growing medium is usually composed of 60% vermiculite, 20% coconut or Sphagnum Peat Moss, and 20% sandy soil.

You can also add a small amount of organic pot soil. Vermiculite can also be added to increase soil’s air-permeability. To increase soil fertility, vermicompost or eggshell powder can be used.

Lack of oxygen can cause root rot in fairy cactus roots. Root rot can occur if the soil isn’t very porous to water and air.

It is simple to check permeability. When watering, the water should flow quickly through the soil and not stop at the surface. Instead, it should slowly seep through.

“Repot and loosen the soil every year to ensure air permeability of the soil.”


When the temperature is between 15 and 20 degrees, sow, plant, or repot. When sowing, maintain high humidity.

Cover the soil with plastic wrap and then remove it when the seeds germinate.

Permeable Terracotta pots are best for your plants. A pot too large will hold water well, while a small pot will restrict root development.

To kill pathogenic organisms, expose the soil to sunlight before planting.

“Planted in a garden, the fairy cactus prefers places where the sun is present and where the soil is loose.”

To prevent root rot and ensure soil permeability, remove all weeds.

Use tongs or gloves when planting, so your fingers don’t get pricked.

To make it more manageable, wrap the plant in a towel.


The fairy cactus can withstand drought and does not need to be watered often. Water the soil thoroughly when it is completely dry.

After placing the pot in the boiling water, slowly water it. Wait for the water to drain from the bottom. Then, empty any excess water out of the tray to prevent buildup.

Their growth seasons are spring, summer, and autumn. To keep the soil moist, water once or twice per week.

Winter is the best time to water less.

It is also important to water your plants with rainwater, distilled water, and not tap water.

Tap water is rich in calcium, magnesium, and other minerals. Soil compaction can be caused by long-term tap water use. It is best to avoid splashing water on the stem during watering, as this could lead to it rotting.


During the growing seasons i.e. fertilize fairy Cactus once per month with a liquid fertilizer (it is for sale here).

Winter is the time not to apply fertilizer. When repotting in spring and fall, a small amount of slow-release fertilizer may be added to the soil.

You should use a nitrogen fertilizer for the sowing period, and a potassium fertilizer prior to and after flowering.

Concentrations of fertilizer should be as low and as minimal as possible.

It is better to apply fertilizer at low concentrations several times than at high concentrations.

If the base becomes yellow or slow-growing, you may have too much fertilizer. Stop fertilizing immediately.


Fairy cactus does not require much pruning. Remove spent flowers and branches so the plant uses nutrients for optimal growth.

Prune spent flowers and branches in the spring to give the plant optimal light, air circulation and nutrition.

The Fairy cactus does not require much pruning, but if you decide to give it a haircut, you should remove its tips of it.


The harvest of the fruits is one of the easiest things to do in the fairy cactus. The fruits that turn red are ready for harvesting.

On its back, you will find a little opening where the fruits are. Avoid any health problems by having the species confirmed by specialists.

Before you start harvesting, it is important to have your tools ready.

Wear gloves or use scissors and any other tools for harvesting. Make sure that you remove all the fruit that has already ripened and fallen off the plant.


The seeds are not the only methods of propagation. The main propagation methods include division and grafting.

Propagation is one of the most important aspects of the life cycle of a cactus, and there are a few methods that can be used.

The division is a process in which the plant is separated into individual plants. The end or side branch of the mother plant is cut with a knife, then planted in the ground.

After watering it several times, many small shoots will grow near the cut. In about one year, when each shoot reaches 3 cm in diameter, it can be removed by cutting off the rootstock with a knife and replanted to form a new plant.

The other propagation method is grafting. Cut off the tip of the rootstock such as the pitahaya stem (Hylo cereus undatus), then place the fairy cactus without its roots in the center of the rootstock.

Use a rope to fasten them together for one to two weeks. After growth occurs between both parts, remove the rope and keep watering them until they can be transplanted normally.

In botany, a rootstock is defined as an underground stem that supports a plant. These stems are usually perennial and provide anchorage for their attached plants. The part of the stem that grows above ground is called a scion (or cutting).

Seasonal Precautions

Increase fertilizer and water intakes during peak growth periods in spring, summer, and autumn.

Avoid direct sun exposure during summer’s high temperatures. Spray water around the plant to cool the temperature, but don’t leave water on the stem. Avoid letting water accumulate in the soil.

Winter: Water it as little or as much as you can, and then stop adding fertilizer.

Pests and Diseases


Anthracnose often occurs in environments with high temperatures and humidity. In the early stage of the disease, slight water spots or brown spots appear on the stem. 

The diseased part is weakened, and small black spiral spots appear on the upper parts. Sick plants should be isolated, affected leaves cut off, and burned. It is then necessary to use the appropriate pesticides.

Blossom End Rot

Stem rot is a common disease of fairy cactus, the pathogenic factors of which include unsanitized garden debris or soil, cold damage, and insect damage. 

In the early stage of this disease, dark gray (or yellow-green to yellow-brown) spots may appear in the tissues of the diseased part.

 They gradually become soft and rot. Later, the stalk tissue rots and loses water until only the dried skin and the center of the stalk remain.

Stem rot can be prevented in two ways.

  1. Expose the soil to sunlight to disinfect it, or buy disinfected cultivation soil to ensure that the soil is clean, loose, and permeable.
  2. Avoid excess water, provide effective drainage and keep the base of the plant dry. In case of stem rot, immediately cut off the diseased part and disinfect the cut with sulfur powder( buy on amazon)or powdered charcoal. Reduce watering, repot and disinfect the soil. At the first signs, you can spray Bordeaux mixture (it sale here) at the rate of 1:100 on the base of the plant, once every 15 days, and this 2 to 3 times.

Root-Knot Nematodes

Root-knot nematodes are soft, white-bodied insect that has two pointed ends. Root-knot nematodes cause the plant to turn dark brown on its stems and leaves, eventually leading to death.

Before planting, heat disinfects the soil and pot to kill root-knot moths. Root-knot nematodes can be sensitive to high temperatures, so high-temperature disinfected cultivation dirt is an effective way to get rid of them.

Viral Disease

The fairy cactus can catch different types of viruses, but the main symptoms are mosaic leaves and local necrosis. On the stem, you may often see chlorotic spots or annular roughness.

The plant is more vulnerable to viral diseases during periods of heat or drought.

Once the disease has been detected, it is important to isolate or destroy the affected plant. Make sure to disinfect all tools that are used in grafting or care.

Spider Mites

Spider mites are a common problem in greenhouses, and they can wreak havoc on the plants they infest. These small creatures live in colonies on the undersides of plant leaves and feed on the plant cells by piercing them with their mouthparts.

 As a result, a leaf that was once green turns red and then yellow, revealing the spider mites' natural green color against the yellowing background. 

The process of getting rid of these insects is simple: wash the backs of the leaves with water, then repeatedly spray a specific pesticide called an acaricide.

Make sure to spray under all of the leaves, as spider mites often hide there to avoid being washed off by rain. Once you’ve treated your plants, keep them well ventilated to avoid suffocation and drying out as you wait for the spider mites to die off.


Fairy cacti affected by aphids show yellow spots or distorted shapes. Small pests are visible on the tender parts of the plant. Eliminate them with water, for larger infestations, spray an anti-aphid product.

Other pests and diseases

Below is a list of less common fairy cactus pests and diseases that may also need your attention.

  • dry rot
  • soft rot
  • mealybugs
  • Rodents

Why Is Its Fleshy Stem Getting Thinner and Thinner as It Grows?

The thinness of the stems can be due to one of three things: insufficient sun, insufficient water, or a deficiency in fertilizer.

It’s important to avoid sunburn when moving your plant from one location to another. Make sure your fairy castle cactus gets at least six hours of sun a day in its new spot. If you’re worried about it getting too much sun, you might want to move it into an area with less intense sunlight for a few days so that it will acclimate properly.

How to Treat Root or Stem Rot?

The most common cause of root and stem rot is excess water. When the soil around a plant remains constantly moist, the roots may begin to decay before the plant is able to use its nutrients.

You can avoid root rot by making sure that your plant’s roots are in contact with the soil. In other words, do not let a layer of mulch develop between the roots and the soil.

If your plant is already showing signs of root or stem rot, you should prune off all infected parts and transplant your plant into a new pot placed in a well-ventilated area while treating it with an antifungal agent such as copper sulfate or trichlorfon (it is for sale here).

Why Does My Fairy Cactus Never Bloom?

Fairy cacti are particularly sensitive to their environment, and they change based on their surroundings. This means that if your cactus is not blooming, one of two things is probably happening (and very likely both): you aren’t providing the right conditions for flowering, or you’re providing all the right conditions but you’ve been doing the wrong things for too long.

First, it is possible that this is not the flowering period of the plant. The time between sowing and flowering can vary between 2 and 20 years, or even more. So don’t worry—it’s perfectly possible that your fairy cactus isn’t meant to bloom yet!

Second, the plant may need more sun, heat, or fertilizer. Increase sunlight exposure and fertilizer inputs, supplement these with phosphorus and potassium or purchase a specific fertilizer to promote fairy cactus flowering.



Anwar Hossain

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

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