Coleus Root Rot (6 Signs, Causes & Step By Step Solution)

If your coleus plant is having some random yellow or brown leaves, it’s time to check whether your plant is affected by root rot or not.

Root rot has to be taken very seriously. If timely action is not taken, it might even kill your plant in a relatively short time.

This article explains everything about coleus root rot including its signs, causes, and possible ways to recover the plant.

Coleus Root Rot Symptoms

If you suspect root rot in your coleus, look for the symptoms like yellow or brown shades in leaves, decaying smell from the base of the plant, very slow or stunted growth, presence of mold, and curly, droopy, or wilting leaves. If multiple symptoms are present, then uproot your slowly plant and inspect the roots. If they are mushy and have a very dark appearance, it’s probably root rot.

Let’s go through each of these symptoms one by one.

1. Discolorreed & wilting leaves

Leaves changing colors is one of the commonly seen signs of many plant problems including root rot.

When your coleus plant has root rot, its roots lose the ability to suck air, water, and other essential nutrients from the soil. This triggers the leaves to preserve water and curl the leaves downwards. 

If the condition does not improve over time, the plant cells in these leaves start to die. As a result, discoloration of leaves happens.

Ideally, the green color changes to yellow and then eventually brown. But, some coleus varieties already have yellow leaves and in those plants, their yellow shade becomes lighter and turns brown over time.

Sometimes, instead of changing colors these leaves directly wilt and dry from their curly or wrinkled state.

2. Poor growth

The majority of coleus variants can grow up to 36 inches in a single growing season (4 to 5 months) if proper conditions are provided. This growth rate makes them one of the fastest-growing houseplants.

If your coleus plant is not growing fast even during its growing season, it may indicate that the plant is suffering root rot.

As already mentioned, rotten roots cannot transport enough air, water, and nutrients to support the health of the plant.

Due to a lack of enough nutrition, the coleus plant will produce small leaves. And, the frequency of those new leaves coming out will also reduce drastically. 

As the root rot progresses over time, the plant will completely go dormant to maintain the existing plant instead of growing new leaves. This makes the plant look stunted even during growing seasons.

3. Presence of mold

The presence of mold or fungus is also a sign of root rot in coleus plants.

Ideally, wet soil is a breeding ground for fungi, bacteria, and many other similar microbial. And, the same wet soil is also the number one cause of root rot (we’ll discuss this in the next section).

So, if you are seeing any white fizzy-like substance on the top layer of your coleus potting soil, then there is a high chance that your coleus is infected with a fungal disease that might have already caused coleus root rot.

4. Rotten Smell

Coleus root rot is nothing but the roots of your coleus plants decaying due to several reasons. And, the basic biology is that whenever something decays, a bad smell is developed.

If you suspect root rot in the coleus plant, try to smell the base of your plant. If a rotten egg smell is present, then there is a high chance that the roots underneath are rotting.

If you use organic matter as fertilizers, you may not be able to distinguish the smell because most of them have a similar odor.

5. Dark mushy roots

So far, we were checking the symptoms that are visible above ground.

But to make 100% sure that your coleus plant has root rot, it is essential to inspect the roots.

For that, you need to remove the plant from the existing plant. Once the roots are visible, examine their strength and color properly. 

Healthy roots are very strong and have light or pale brown color. However, roots with soft and dark brown with a mushy appearance indicate the presence of rotting.

Coleus Root Rot Causes

Root rot in coleus is mainly caused by overwatering the plant. These plants have very moderate water requirements and when it is more than what is needed, it will trigger coleus root rot. Some other causes like poor drainage, fungal infection, and overfertilization cans also lead to root rot in the long run.

1. Overwatering

If your coleus is having root rot, overwatering is the main culprit.

Often many beginner houseplant owners overwater their plants thinking that they will grow faster. But, in reality, they are just killing the plant slowly.

Coleus plants are native to subtropical regions of the world and have moderate water requirements. 

Simply stick your index finger 2 inches into the soil before your regular watering cycle to see if you are overwatering your pothos. If the soil is moist, you’ve likely overwatered your plant and you should reduce the frequency of your watering cycle.

2. Poor soil and drainage

Everyone over-water their plants occasionally, and no one will deny that. And what helps in those occasional overwatering is the presence of a proper coleus-specific soil mixture.

When you have well-drained potting soil with enough water holding capability, it will remove the excess water and store only the amount of moisture needed for the coleus plant.

On the other hand, if you are using some damp soil, even a little bit of extra water will lead to coleus root rot.

3. Fungal infection

Numerous factors, like overwatering, infected soil, etc, might lead to a fungus infestation. Furthermore, excessively wet soil is heaven for fungi and other water-borne pathogens.

Mostly, water-borne pathogens like Pythium, Rhizoctonia, and Phytophthora are the culprits in case of coleus root rot.

In most cases, these pathogens are introduced to the coleus plant as a result of using infected water. If this water touches the leaves, the leaves will also turn brown and black.

4. Overfertilization

Just like how overwatering is killing your coleus plant, overfeeding will also kill your plant in the long run.

Many beginners think that providing too much fertilizer will boost plant growth. And, to an extent it is true.

But the problem happens when the roots cannot handle the aggressive growth. As a result, they start to rot and die.

Additionally, too much fertilizer in the soil will hinder the soil’s ability to store air inside the pockets.

How To Save Coleus From Root Rot?

If you suspect the coleus plant is suffering from root rot, immediately repot the plant in a new container with fresh soil. While repotting, it is recommended to treat the roots with a fungicide and hydrogen peroxide solution to improve the health of existing roots. After repotting, make sure to water only when the top two inches of soil is dry.

Repotting your coleus plant is a straightforward process. But, it is recommended to get ready with all the essential items before moving your plant from the existing pot.

Here are the items required,

• New pot & fresh coleus-specific soil
• Hydrogen peroxide
• Fungicide
• Rooting hormone
• Sink with running water
• Sterilized scissors

If you got everything ready, follow the below step-by-step process to save your coleus from root rot.

1. Slowly uproot the plant from the existing pot without damaging the stem or root.
2. Once the plant is completely taken out, clean the roots under running water to remove existing soil. Make sure that existing soil is completely removed.
3. Inspect the roots to find damaged roots. Damaged roots will be dark brown or black. They also have a mushy appearance.
4. Using sterilized scissors remove all the fully damaged and partially damaged roots from the base.
5. Apply rooting hormone and hydrogen peroxide solution to the remaining roots.
6. Apply fungicide to the new pot and fill 1/4th of the pot with potting soil.
7. Place the coleus plant inside and fill the remaining soil. Leave at least 3 to 4 inches of space at the top to water and fertilize the plant efficiently.

Once repotting is done, water the plant thoroughly so that the soil and root will be set together. It will take at least two weeks for the roots to bind in the new soil.

Once the plant recovers, make sure that you never overwater the plant again.

Coleus Root Rot – Frequently Asked Questions(FAQs)

If you are seeing root rot in the coleus for the first time, then probably you will have a lot of doubts. And, in this section, I will be answering some of the most frequently asked questions related to coleus root rot that was asked on different online threads.

Wrapping Up

Among many problems faced by houseplant owners, coleus root rot is one of the issues that need timely action to save the plant from dying.

If you suspect root rot in the coleus, check for all the symptoms that are shown above the ground. And if you see a few of them, be ready to repot the plant on priority after inspecting the roots.

After repotting, make sure that you never overwater your coleus again.

Sources

To back up the information we provide in our articles, the Plantials team only uses high-quality sources published in peer-reviewed university or scientific research journals.

1. Bio Control Potential Of Pseudomonas Fluorescens Against Coleus Root Rot Disease, Journal Of Plant Pathology & Microbiology.
2. Evaluation Of Vermicompost Doses For Management Of Root-Rot Disease Complex In Coleus Forskohlii Under Organic Field Conditions, Australasian Plant Pathology
3. Medicinal Plant Coleus Forskohlii – Disease And Management, Central Institute Of Medicinal And Aromatic Plants, India
4. Root Rot Diseases In Plants: A Review Of Common Causal Agents And Management Strategies, Agricultural Research & Technology Journal.