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Why Is My Cactus Turning Brown – 5 Likely Causes!

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It can be difficult to see your cacti plants showing signs of illness when you have cared for them with so much love. Although it is not too hard to care for the cactus, it can still turn brown and display sickness symptoms. This can put you on a frantic search for “Why Is My Cactus Turning Brown?”

You don’t need to get confused or worried as we have got the answer right here. Keep reading to get your answer to “Why is my cactus turning brown?” and jump on the path to making them healthy again.

Why Is My Cactus Turning Brown
Why is my cactus turning brown at its bottom – via Reddit

Why Is My Cactus Turning Brown – 5 Reasons

The brown color of your cactus can be for several reasons. They could be environmental reasons or giving the right conditions for the cactus to remain green and lush. Let’s find out the reasons behind your query- Why is my cactus turning brown?

Corking or Ageing

First, you should eliminate the natural cause of your cactus turning brown. If your cactus plant has reached a mature age, the chances are that the browning is due to that age. In this case, the plant starts to turn brown or grow “bark” from the bottom or near the soil.

The brown material is known as “bark” because of its hard, wood-like structure, and so the process is known as corking.

A clear sign of aging is the plant turning brown from the base while the rest of the cactus is green and healthy. If it turns brown from above, it is not age but something else.

There is not much that can be done to prevent or reverse aging. You can delay it by providing optimal conditions for growth. But once the cactus starts corking, you can only wait with patience.

Rotten Root

Root rot can destroy your cactus plant because mostly it can’t be detected. It starts from the inside and spreads outward. By the time you notice a root rot, it will already have spread to an unrecoverable place.

In a root rot, the browning will start from the base, the stem will turn yellow, mushy, and soft, and you will notice brown spots on the soft places. These brown spots and softness show that the root rot is moving outwards now. You must stop watering the plant as soon as you spot the signs of root rot.

To save the rotting plant, you must separate the affected areas from the unaffected parts. For this, you need a sharp blade, knife, or cutters to chop off some parts of the cactus.

Now you can either cut all the parts where browning has spread or chop off the healthy stem. It is better to cut the healthy stem, which can then be planted in a new pot in different soil, and you will have another cactus plant.

If the root rot has not invaded a large part of the plant, you can also cut off the affected parts. Apply sulfur powder after cutting on the wounded parts. The plant would grow back if the root rot case were not severe.

You can prevent root rot by not overwatering the plant and keeping the soil well-aerated.

Why Is My Cactus Turning Brown 2
Why is this cactus turning brown – via Reddit

Infestation of Scales

Scales are small insects that can take over your cacti and turn them brown. If you see any brown and yellow spots, you could be dealing with a case of scale infestation. Scales thrive on cactus juices, and they need to be dealt with immediately, or the insect infestation will take over the entire cactus selection.

For a small, contained insect attack, you can wash them off with soap and water. You could also use detergent instead of soap.

Wiping them off with horticulture oil will kill all the insects right away. If the infestation has gotten out of hand is spreading fast, you might have to take the help of a chemical insecticide.

Mite Infestation

Mites are small red spiders. They are not insects but a form of pests. Mites suck out all the juices from the cactus plant and will destroy it completely. To spot these pests, look for spider webs on the cactus because it is hard to spot mites as they are extremely tiny.

A clear sign of mite infestation is the browning of cactus from the top, with yellow-brown spots appearing at certain points. The browning will be in rusty patches and occur at the tip of the plant. Mites usually infest indoor cactus, or the plant may already be infested if you brought it from outside.

The best way to deal with mite infestation is to spray the plant with fast or pressured water from a hose. The pressure of the water will wipe off all the mites. Also, mites thrive in dry, hot environments, so watering with pressure from above discourages their growth.

Browning Caused By Sunburn

Sunburn occurs due to too much sunlight or excessively bright light. If the plant is discolored from the top and on the sides facing the sun, the sunburn is mild, and the plant can still be saved.

In case there are hard brown patches at the top and sides, the sunburn damage is permanent and can’t be reversed here. Mild sunburn damage can be managed by moving the plant to a shaded area.

Although cactus is a desert plant, not all varieties are accustomed to living in the sun. Many cacti won’t be able to survive for long in the bright sun. Research about the sunlight needs for your king of cactus and act accordingly.

In some cases, the cactus has been grown indoors with artificial light and is not accustomed to direct sunlight. Here you need to introduce the cactus to sunlight gradually. Keep it in direct light for some time and then increase the timing over weeks.


Cactus can be grown indoors and outdoors. They make for wonderful house plants. However, their needs might be a bit different from what you are normally used to. Do some research on the variety of cactus you are growing to ensure optimal conditions for the plant.

Now that you have your answer to “Why is my cactus turning brown,” you can get working for the solution? Take care of your cactus, and let us know your comments.