Mold in Succulent Soil ( Why And How? )

Not all mold in succulent soil is beneficial for the plant’s health. There are fungi which are pathogenic, and which would cause diseases in plants and in humans. 

So, this article presents in-depth guidance on the root causes for succulent soil molds and the modes of getting rid of them. 

So, if you are a succulent grower, I am sure it is indispensable  to have the knowledge in this aspect . So, I urge you to read this article since it will give you an insight on this subject.

Mold in Succulent Soil

Why is there mold in succulent soil?

There are few factors which would cause this condition. For example, excess watering, unhealthy soil, lack of oxygen in soil, lack of sunlight and poor maintenance are some of the prominent causes which could cause this condition. 

Having said that, fungi is a crucial aspect of healthy soil. It is what sequesters carbon. Further, that is responsible for the decomposition of the organic matter also. Once the soil decomposes, it would allow the plants to absorb the nutrients.  

01. Too much water

The occurrence of the mold in succulent soil is natural. Usually, the fungi spore stays rested and dormant in soil for years. So, when they get favorable conditions for them, it would be like a wake up call for them. 

So out of all these, the excess water in soil is a prime factor which would cause soil molding. So, avoid over watering the plants. 

Further when you water, you need to angle the horse without letting the plant get wet. Moreover, do not spill water on the plants leaves as then it would moisten them. Instead try to water the plant’s base directly.

The growth of the mold can take place whenever there is moisture available  in any surface. Usually, mold takes place from the spores of them and whenever they land on any surface, they would become mold at the end. 

whenever the perfect surroundings are available for them, they would become active. As you may already know succulents have water conserved in their bodies and they are not the type of plants which would absorb water in excess. 

So, if you supply a lot of water for them, it will lead to the sogginess and the dampness of the soil which would pave the way for mold development in the soil.

02. Unhealthy soil

When I say unhealthy soil, one might think that I am referring to soil mixes which have bacteria and fungi. 

No, you still want some percentage of healthy bacteria and mold in succulent soil as they would be more like bodyguards and protect the plants from pathogenic fungi. 

However, consider that if microorganisms in your soil are imbalanced  then there will be a high probability for the pathogenic fungi to be more active in the microscopic community.

If you are wondering what would pave the way for unhealthy soil , it would be mainly a repercussion of using pesticides. 

So, to overcome this challenge, you may consider using organic no dig gardening methods. However, if you practice these tips and still if you come across these, chances are that what you used to grow the succulents is already contaminated. So, be mindful to choose a soil mix which is sterile.

03. less oxygen in soil

Consider that your soil mix doesn’t have sufficient oxygen in store. Then, that would be perfect conditions for the pathogenic fungi and for pathogenic bacteria as well. 

In simple words, they would be perfect breeding places for these pathogenic organisms. Ultimately the healthy bacteria  would find it difficult  to combat  with the harmful pathogenic microscopic   organisms and the pathogenic organisms  would be more dominant  in the soil mix.

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Ideally you need to increase the air circulation of the soil. Do not wait until things get out of hand and act smartly and swiftly to overcome them well in advance. Unless there will be major severe repercussions which would be fatal on your precious succulents.

Try  to avoid using heavy machinery whenever  possible which would also be a cause which would result in this condition. 

Further try to cover the crops also so that it would protect the barre soil from rainfall. In addition to that you may also make use of a rototiller  which would be ideal to deal with these kinds of conditions. However, it would make leaves a compaction layer  in the soil.

04. Lack of sunlight

Lack of sunlight is one more common reason which would contribute mold in succulent soil. 

Succulents are sunlight fan lovers.If you have cultivated them outdoors, they need to have at last six hours of sunlight. 

On the other hand, if you had cultivated them indoors, ensure that you place them at a bright sunny spot. Literally it has to be the brightest spot at your home. 

So, if your beloved plants are deprived of adequate sunlight, it would literally pave the way for mold build ups in the soil.

05. Poor maintenance

You need to provide a minor maintenance and supervision to grow the succulents. That said you still need to spend some time and look after them well so that it would help the plants to grow well as well as healthily. 

If you just keep neglecting your plants and let them grow without providing any care treatment, those conditions would be quite fascinating for the pathogenic fungi.  

When I say poor maintenance , that includes the lapses in watering, poor lighting and lack of cleaning as well.

Mold in Succulent Soil

How do you get rid of mold in succulent soil?

Prevention is better than cure. So, keeping that in mind, I would say best is to try all the preventive measures which would help you to avoid these pathogenic mold  happening in your soil.  

If you just act normal and let the fungus take over your plants and after some time if you wish to apply fungicides, it will only create more trouble for you and for the plants as well.

The more elements you add to kill the harmful organisms, the more the beneficial  organisms would kill. 

Healthy organisms are quite crucial for the healthy prevalence of the soil . So, if you apply too many fungicides , it would also be badly affected too. 

To reiterate, not all fungi are harmful for the plants. However, if you come across any white fuzziness in the soil that literally means the soil is under attack by pathogenic fungi and you need to act swiftly to overcome them.

So, the following is how you should get rid of the fungus.

01. Remove diseased plant part

The very first thing you could do to overcome mold in succulent soli is to remove  the deceased plant parts. However, it would depend on the severity of the fungi which has attacked your beloved plants and the soil. 

If the mold attack has spread on a minor level, you may simply snip off the diseased leaves or any other parts of the plants.  

Furthermore, I recommend you remove some healthy leaves also which would allow the plants to have more aeration. 

However, keep in mind to not cut off 30 % of the leaves as then it would badly affect the photosynthesis process of the plants.

02. Improve condition

In addition to that,  if there are lapses in the growing conditions it would also lead to mold in the soil. so, considering that the succulent soil is waterlogged, then I suggest you repot the plants. 

In addition to that you may also place them in the open greenhouse also. However, keep in mind to open the doors so that there will be more air coming in.

See also  Brown Spots On Succulents | Reasons And Prevention Methods |

Apart from that I suggest you rotate the paces of  the plants where you have cultivated them. It would also help the plants to overcome any occurrence of pests, diseases  or any other occurrence of mold . 

Furthermore, never spill water on the leaves of the plants. If you accidently do so, take very good care of the soil.

Go ahead with a top-quality compost which would ensure that there will be no microorganisms established in your soil. 

Furthermore, consider that you have used fungicides a lot, then chances are that it would have killed many beneficial organisms also in the soil mix.

03. Fix the reason

If you could spot mold in your succulent soil, that literally means something is not right in the soil mix. 

Ideally you need to apply an excellent compost or even compost tea to do this task. I suggest you suspend applying fungicides and observe what exactly has gone wrong in your plants. Literally try to figure out the root cause for that. 

You may think, you will have to spend more time to rectify these. However, if you spend some time and effort on it and try to identify the root cause, it would be easy for you to remedy them accordingly.  

Unless you imagine how challenging it would be to  deal with these fungi for so long.  Bear in mind that it would be cost effective also as you do not have to spend so much money on purchasing the fungicides etc.

04. Fungicides 

Applying fungicides is not always bad. There are times where you have to make use of them at some point of time. 

If you spot fungi in the soil even after you took care of them well. I suppose using fungicides periodically would be a great solution here. 

Keep in mind that you need to apply the fungicides depending on the symptoms you can witness. I recommend you save your pants by using pet and human friendly  fungicides  if the requirement arises. 

That said you need to still figure out what root cause has paved the way for the build up of the pathogenic mold.

Mold in Succulent Soil

Related questions

Will vinegar kill fungus in soil?

You could make use of vinegar to kill the fungus in the soil. However, chances are that it may badly affect the overall health of the succulents as well. 

Keep in mind that the succulents which are battling with mold are somewhat weak when compared with the healthy plants. 

So, if you end up using vinegar and let them get in contact with the plants, it will badly affect the plants too. 

That said, if you have to make a choice between vinegar  and chemical fungicide, I will say the best would go for the vinegar. 

Vinegar is cost  effective,  and it has less effect on the health deterioration  of the plant when you compare them with the inorganic chemical fungicides.

Will baking soda kill fungus in soil?

Yes, baking soda will kill fungus in the soil which have spread in significant numbers. However, I recommend using them as foliar spray. 

That said, if your succulent’s soil is going through these conditions on and off, I recommend you proceed with using baking soda. 

Bear in mind that baking soda does not lead to the same repercussion of what chemical fungicides  do for the plants.

If you wish to use baking soda, you may first fill a spray bottle with water. Next, mix a few drops of vegetable oil into it. 

After that  add a teaspoon of baking soda and stir it well. Now it is the time for you to spray it on the plants as well as on the soil.

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However chances are that it may even be fatal for the  beneficial fungi in the soil too.

Will bleach kill fungus in soil?

You could make use of bleach to kill the fungus in soil too. Bleach is mainly used for sterilization  purposes. This literally means it would kill the bacteria and fungi as well.

Does  boiling water kill the fungus?

To answer the question first, Boiling water does kill the fungus in the soil.  You may simply take the contaminated soil and pour boiled water into it.

Once you use sufficient boiling water, the soil would be sterile which you could use for potting purposes. That said, bear in mind that boiling water may eradicate the essential nutrients of the plants as well.

Is mold in plant soil harmful?

To answer the question whether the mold in plants would be harmful, no it is not. Usually mold, fungi are prevalent in the soil mixes

Can You Test Soil for Fungus?

Yes, you can test soil for fungus. In fact, you need to regularly check for fungus, and it should be a part of your gardening activity. 

There are test kits which you could make use of to do this at home. However, they are not the best as you cannot really rely on the results they give. 

So, it would be better if you could just consult your local experts and see whether they have any soil testing program which you can afford.

In addition to that you may also send a sample of your soil to a soil technician and get that checked. There could be different labs which will practice different approaches, so ensure that you select a person who has gained recognition for their work. 

However, when you send the sample, ensure that you send it in aerobic conditions unless it would give you inaccurate results. 

Further if you find out there are normal pathogenic spores in the soil mix, you may just ignore that as it is quite normal.

However, if you found out that there are other microorganisms , that would be attractive for the other harmful fungi.

How Do I Identify the Different Types of Mold?

You could identify the different types of mold by simply looking at them. so, if I briefly elaborate  on them, soil fungus would tend to look like white stringy clumps. There are numerous types of mold which you may come across.  

Leaf spot is a commonly spotted mold type, and you could see them as spots which are discolored. They would most probably be either yellow or brown. 

If you come across any, I suggest you remove the infected parts. If it keeps spreading, you need to treat them more. 

Powdery mildew and garden fungus are two more mold types which you may come across.  Powdery mildew will appear on the leaves first.  Some of the garden fungus are anthracnose, blight, rust, clubroot etc.

If I briefly touch on how to identify the Anthracnose, they will appear to be black stains on the leaves. You could spot blight as brown spots on your plants. 

On the other hand , you could identify rust as roundish blisters on the stems. Lastly, you could clubroot by observing the plant roots. They would be mutated and swollen once they suffer from clubroot.


Before you treat the fungus in your succulent soil you need to identify what kind of fungus you are dealing with as chances are that they could either  be beneficial or  harmful too. 

So, if you figure out that pathogenic fungi have formed here, you need to act smart and try to eradicate them. 

To do that, you need to water the plants moderately and let the beneficial microorganisms perform their functions also. 

Credit to : Desert Plants of Avalon
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About author

I’m Dr. Chamika, As a hobby love talking about plants and showing you that taking care of indoor plants. My website is knowledge I’ve learned over the years and continue to learn about growing succulents. If you’re a succulent lover, then you have come to the correct place.