Root rot is the main problem that people face when they grow Dieffenbachia. This deadly root disease can kill your plant in less than a week.

To save your dumb cane plant you need to quickly identify the cause and fix it. Yellow leaves, Bad smell from the potting soil, waterlogged soil, etc are the first signs of Dieffenbachia Root Rot.

The main causes are planting your Dieffenbachia in the wrong type of potting soil and overwatering it.

If 50% of your Dieffenbachia plant is healthy, you can easily save it by repotting it and cutting the infected roots.

But if the fungus is all over the plant, then you should propagate it.

In this article, I’ll explain Why Dieffenbachia has root rot and How to Identify and What you can do to fix it.

Identify Dieffenbachia Root Rot

The first step is to identify the Root rot. Because sometimes Dieffenbachia leaves turn yellow due to dryness not because of root rot.

So, you cannot reply on just one sign. You need to inspect your plant closely and check every angle of it.

Below are some 100% sure symptoms of root rot in Dieffenbachia.

Brown and Mushy Roots

Take the plant out of its pot and inspect the roots. If they are brown and release an unpleasant smell then they are definitely infected by root fungus.

When you touch the roots, you will see that the outer layer peels off easily.

The extra water in the potting soil is rotting the outer layer easily. Because it is the only defense of the roots.

Mold on the Top Surface of the Soil

When you give excessive water to your plant the potting soil absorbs it in large quantities. This makes the soil waterlogged for a long time.

This speeds up the growth of soil fungus and as a result of it, you see the formation of mildew or white mold on the top surface of the soil.

This condition is common when the pot you are using does not have a draining hole.

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Dark brown spots on Leaves

Brown spots on Dieffenbachia leaves are the early sign of root fungus. This means the problem is in the starting stage and you have enough time to save your plant.

In some cases, the leaves also develop brown tips along with dark spots. Mostly the spots are on the leaf tip side.

Dieffenbachia Leaves Turning Yellow

Yellow leaves are also an early warning sign. When the roots stay in excess water for a long time. They become unable to transport the nitrogen and other essential nutrients to the leaves.

We all know a good percentage of nitrogen gives green color to the plant leaves.

Due to the absence of a sufficient amount of N Dieffenbachia plant leaves start turning yellow. At the first stage, the tips turn yellow, and then the whole leaves.

In the last stage, the yellow leaves turn brown or black and fall off the plant.

Slow or No Growth

Infected roots cannot absorb a sufficient amount of nutrients and water from the soil. This deficiency of important nutrients slowdowns the normal growth of the plant.

If you do not fix it on time the plant completely stops growing and this stage is called the stunted growth stage.

In the first stage, you will see small size leaves and in the last stage of infection, your plant becomes weak, and leaves start falling off.


Because the roots are damaged and they cannot absorb water and nutrients. This results in wilting and weak plants.

The brown leaves do not get proper moisture and the leaf joints cannot hold their weight.

What triggers root rot in the Dieffenbachia plant?

The main cause of root rot in Dieffenbachia is extra moisture in the potting soil. This invites root fungus bacteria.

Sometimes this fungus starts from the upper part of the plant. The leaves and stem got fungus and then it transmits to the root section.

There are many other reasons responsible for Dieffenbachia Root Rot all of them are discussed below.


Excessive moisture in the soil trigger Dieffenbachia root rot. The extra water makes the soil heavy and closes the air pockets.

This blocks the supply of fresh oxygen which results in root rot.

Dieffenbachia roots need fresh oxygen to prevent root fungus disease. It also improves the root functioning and your plant produces bright leaves.


Water your plant only when the top surface of the soil becomes dry. This will keep your plant roots protected from root rot.

Use your finger to check the soil moisture.

If you accidentally overwater your plant then immediately place it in the bright light. Because the bright light gives warmth to the soil and this evaporates the excessive water.

Just make sure that all sides of the plant pot get an equal amount of light.

Do not place it in the direct sunlight to speed up the water evaporation. Because direct sunshine will burn the Dieffenbachia leaves.

Place your plant on a sunny window where it can only get morning sunlight or indirect bright light.

Poor Drainage

Poor drainage increases the chances of root fungus. Because the water stays in the soil for a long and cannot find a way to drain out.

This makes the soil soggy and reduces air circulation.

The wrong kind of potting soil is the main cause of it. When you use potting soil that contains a heavy amount of organic matter and clay.

This automatically blocks the water from draining out.

Secondly, if the plant pot does not have holes at the bottom the extra water did not find a way to go out. This again infects the roots and causes root rot.

Draining holes are tiny holes at the bottom of the pot. They are made by the manufacturer to give a nice draining path to extra water.

This is the reason we put saucers under the plant pots so that we can collect the extra water in them.


The first thing you need to do is use the pot that has draining holes. You should use clay or terracotta plant pot.

These two materials are porous in nature means they have tiny pores. These pores allow the outside air to touch the soil and evaporate the extra water.

The last thing is you need to use well-draining potting soil.

There are two formulas that will do best for the Dieffenbachia plant.

1 part perlite + 1 part peat

Regular potting soil + perlite + peat in equal parts.

Too Large Pot

Use an appropriate size pot for growing Dieffenbachia plants. Even if you are repotting it, you should use only one size bigger pot.

Because too large pots contain too much soil and after watering, they hold a large amount of water for a long time.

This extra moisture in the soil invites many problems and one is a root fungus disease.

On the flip side, too small plant pots put negative pressure on the roots. They get compressed and cannot perform a proper function.

This disturbance in the normal root function results in weak plants with weak roots. The compact environment increases the chances of root infection.


The best way to avoid this problem is to use the correct size of the plant pot. Now the question is how you will measure the correct size of the pot?

The general rule is you should use a plant pot that is 2 to 3 inches wider than the root ball size.

For repotting, use terracotta pots and repot your plant once in 2 years or when the soil gets depleted.

Cold temperature

Weak roots are an easy target of fungal pathogens. The cold weather and frost damage the Dieffenbachia roots and they get weak.

This weakness invites root rot bacteria.


To avoid temperature-related root damage please keep the grow room temperature in between 55 to 75 degrees F. This is the ideal temperature range for growing and caring Dieffenbachia.

Bring your plant inside in winter if it is growing outside.

You can use heat mats to give a nice warmth to the plant roots.

Watering in Winters

Winter is the dormancy period of the plants. This means your plant is not growing at this time of the year.

So, it needs less water as compared to the summer.

When growers do not care about the season and they continuously give water every week in the winter season, This results in Dieffenbachia root rot.

To avoid this condition, you should not water your Dieffenbachia in winter as you water in the summer season. Always check the soil before watering it especially in the winter season.

How Do You Save Dieffenbachia from Root Rot?

The first step is immediately to stop watering the plant. Then take it out of its pot and remove the soil to inspect the roots.

You can use a soft brush or cotton cloth to clean the roots. Then use sharp shears to cut the infected and damaged parts of the root ball.

After then prepare the new pot with new potting soil and makes sure the new pot has some draining holes.

Then plant it in the new pot and do not give water at this time. You should wait 24 hours and then spray some water on the soil to keep it slightly moist.

Place it in the bright indirect light and give regular care.

Your plant will heal in 15 to 20 days. When you will see the new leaves, this means your plant is safe and healthy.

How to Propagate when roots are completely destroyed?

Stem Cutting

Stem cutting propagation is the easy method of Dieffenbachia propagation. This step is necessary when 60% of the root ball is destroyed.

Cut multiple cuttings of the healthy dumb cane plant

Put the cutting in clean water and place the glass in a warm and humid location

Within a few days, your cutting will develop new leaves

This indicates that your cutting is rooting

Once the leaves grow 1 inch long then you can transplant them to the final pot

Root Division Method

This method is only useful when your Dieffenbachia root rot is only in the 1st or 2 stages.

Take the plant out of its pot

Divide the roots into different sections

Use sterilized shears to cut the divisions

Now plant healthy root divisions in different pots and give some water

How to treat Dieffenbachia root rot?

You have two options one is using a professional approach means using chemical fungicides. The second option is using homemade solutions like Cinnamon, Charcoal, etc.

I prefer professional procedures because they give quick results and this method is almost guaranteed.

In the case of Dieffenbachia root rot, you need to take your plant to a botanist or to your local garden store. There they identify the type of root fungus and its degree.

Then they recommend some fungicides and you will save your plant in easy steps.

Some fungicides are costly but the results are guaranteed. They have years of shelf life you can use them in the future if any other plant got root fungus.