How To Treat The ZZ Plant Stem Rot [Causes & Solution]

Your ZZ plants can often get stem rot, which is a very dangerous disease for them. And if you don’t give your immediate attention, stem rot will severely injure your precious ZZ plants. But if you spend a little time treating your plant, it will surely recover from stem rot. 

Yet, stem rot weakens the plant very fast and if you are late in starting the treatment you won’t be able to save the plant. But here is the good news for you; In this article, I have discussed A-Z of stem rot problems, which includes how to identify this disease by seeing the symptoms, how to treat them, and lastly how to protect the ZZ plants from future stem rot attack. 

In addition, If you follow this article thoroughly, you will be able to work with other fungal diseases like root rot and crown rot. 

So, without making any delay let’s get started-

What Is the Stem Rot Of A ZZ Plant

ZZ plant stem rot is a fungal problem caused by a fungus of Rhizoctonia or Fusarium genera. These fungi are soil-borne and they stay dormant in the soil for a long time. Their infection damages and weakens the plant very harshly.

Stem rot is usually transmitted by water. When the weather is moist and humid, fungal diseases get a favorable environment to attack. And It spreads very rapidly and ends up killing the ZZ plant within a few days. 

What Does A ZZ Plant Stem Rot Look Like

 ZZ Plant Stem Rot

When a ZZ plant is suffering from stem rot there are black spots on its stem near the soil level. 

As the disease advances the black spots expand in diameter and sometimes several spots merge together and turn a considerable portion of the stem into black.

Eventually the stem lodges and breaks at some point. Moreover, the leaves start to wilt and become yellow. The yellowing starts from the lower leaves and gradually reaches the upper part of the plant. 

Since it’s a soil-borne disease, it affects the root system too. The roots become grey with a bad smell coming out of them. If the infection is severe the ZZ plant dies in a short time. 

What Causes Stem Rot In The ZZ Plants

Stem rot is caused by several reasons. Sometimes two or more reasons can combinedly cause stem rot in a ZZ plant. So it’s really important to know the causes so that we can take control of it and prevent stem rot from happening in the future. 

Now, let’s check out the reasons briefly:


It’s the first thing that causes stem rots in a ZZ plant. Because ZZ plants are more adjusted to drier conditions so they don’t need so much watering. If you overwater them they will easily get affected by stem rot. Because the fungus responsible for stem rot loves soggy and water-logged soil conditions. 

Incorrect Soil

Stem rot fungi are soil-borne so the soil is one of the main reasons for stem rot of ZZ plants. Compact and clayey soils hold moisture for a long period and this creates water logging conditions and helps to cause stem rot. 

Wrong Drainage 

If the ZZ plant pot doesn’t have enough drainage holes no matter how perfectly you water them, your plants will easily suffer from stem rot.

Wrong Kind of Pot

The pot size is very important. If the pot is too small for the plant the roots won’t be able to grow freely. On the other hand, if the pot is too big then the soil will hold too much moisture. This is not good because the overwatered situation will invite stem rot in your ZZ plant. 

Fungal Infections

Pathogens like Rhizoctonia, Fusarium, or Pythium cause stem rot. So if they are present in the soil you won’t be able to prevent stem rot by other measures. You have to get rid of them from the soil first. Otherwise, the fungal infection will continue to kill the plant. 

How To Treat Stem Rot Of A ZZ Plant

You have to treat your ZZ plant very promptly. Because it affects the plant very quickly and at one point the plant becomes too weak to survive. But if you start to save them rapidly then your ZZ plant will survive and thrive in the corner of your home.

Sometimes the control of stem rot may seem a bit tricky. But trust me, it’s not that hard if you follow some step-by-step process. 

Here is the full guide you can follow to solve the stem rot problems of your ZZ plant: 


As we know that stem rot fungus lives in soil, the first thing you need is to change the soil. Carefully shake the pot and remove the plant gently out of the pot. You can use a spade to shuffle the soil to make the work easier. But always make sure not to injure the roots while pulling. 


Now wash the roots and the lower portion of the stem in running water. In most cases, roots are affected too. So, if you see some roots are mushy and slimy, cut them off with sharp tools. Dispose of the debris very carefully without letting them mix with other plants.


After that, re-plant your ZZ plants in fresh soil in a suitable-sized pot. Add sand or perlite to your soil mix to help with drainage. Also, you can buy houseplant potting mixtures from the store (our pick: Miracle-Gro Indoor Potting Mix). Make sure the pot contains drainage holes big enough to drain the excess water. 


After planting the ZZ plant in the newly prepared soil, water them immediately to reduce the transplant shock. And put them in a corner where there is indirect sunlight. 


Now that we are done with planting it’s time to apply a fungicide. There are many types of fungicide available in the market but you have to choose the right one for your problem. Read the instructions very carefully and apply them by following the label directions (Our Pick: Bonide Copper Fungicide).


There are a few additional things to do. After applying the fungicide you can cut the yellow leaves of your ZZ plant to reduce extra pressure from them. The yellow leaves won’t turn green, rather they will keep taking nutrients and water from the plant. So, it’s better to get rid of them. 


Don’t just fertilize right after replanting them, wait for a few days. This is because after transplanting in a new pot the roots become very vulnerable and delicate. If you fertilize at this time, the root will burn and get injured. As a result, your ZZ plant will become sick again. 


Now it’s time for you to wait and give the plant some time to recover itself. Sometimes it might take longer than usual so be a little patient. Meanwhile, keep watering them when the soil is dry and give them 4-5 hours of indirect sunlight.

Note:  While handling the ZZ plant be a little careful because the sap in the plant contains calcium oxalate that is slightly toxic. It can irritate the skin when in contact. So, to avoid skin irritation it’s better to wear gloves. 

If in any case, the sap gets in contact with the eyes, wash with plenty of water immediately and see an eye doctor. 

DIY Fungicide Solutions 

Homemade fungicides are also a very effective solution for controlling ZZ plant stem rot. And they are very simple to make. Let’s check some of them out: 

#Recipe 1:- Homemade Pyrethrin Fungicide

Daisy flowers contain a chemical called pyrethrin that contains natural fungicidal properties. If you have daisy flowers in your garden you can easily make a nice fungicide out of it.


  • Daisy flower 
  • Water
  • Liquid dish soap


  • Pick some full blooms from your daisy plant
  • Dry the daisy flower in a cool and dry place 
  • Store the dry flower heads in a tightly sealed container. You can store them upto six months in a freezer
  • Now ground one cup of daisy head
  • Mix it with enough water and add a few drops of liquid dish soap
  • Apply on the ZZ plant near the base of the stem

# Recipe 2:- Baking Soda Spray Recipe


  • Baking Soda ½  teaspoon
  • Few drops of liquid soap
  • 500 ml of water


  • Combine water and baking soda
  • Then add the liquid soap
  • Pour as much as required on the base of the ZZ plant 
  • Apply 2-3 times a week

Note: Do not go overboard when using homemade fungicides. Because too much of their application will injure the roots. Always apply according to the size of your ZZ plant.

How To Prevent A ZZ Plant From Getting Stem Rot

First, start with watering techniques. Always water the soil when it is dry. You don’t have to water on a schedule. Because moisture needs of soil change with many factors like weather conditions, size of the pot, size of the plant, etc. So that means your ZZ plant won’t always need the same amount of water. Get a moisture meter so that you know when and how much to water (Our pick: Atree Soil Soil Tester Kits with Moisture, Light, and PH Test for Garden).

During dry summer water frequently but in fewer amounts. But during winter water them very little once every 3 or 4 weeks.

In case you have overwatered the ZZ plants, put some dry leaves or shredded newspapers over the soil. This way extra water will be soaked up. 

Never use the old soil when replanting the ZZ plants. Root rot pathogens are soil-borne so the old soil will bring back the disease even after treatment. Always use clean and new potting soil.

Always keep the soil in check and notice the drainage rate after watering. As the plant grows, shift them into bigger pots with enough drainage holes.

Frequently Asked Questions (FAQs)

1. Can Plants Recover From Stem Rot?

Yes. If they are not severely attacked by stem rot and if they are properly treated then they will recover. 

2. Why is my ZZ plant stem turning black?

Stem rot and root rot both can cause black stems in your ZZ plant. The blackening of the stem usually starts from the base of the plant and gradually reaches upward. 


Stem rot is a very annoying disease of the ZZ plant. So, if you want to save your favorite house plants from stem rot you always have to take precautionary steps. On the other hand, when they are already attacked by stem rot you have to be very quick in action and help them to recover. 

I have tried to include every information about stem rot solutions for your ZZ plant with step by step process. I hope this was helpful enough to cure your plants and set them back to normal and healthy houseplants to brighten your day. 

Don’t forget to share your feedback with us about the stem rot problems of ZZ plants or any other houseplants.

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