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What Are The Common Fungal Diseases In Houseplants?

Updated October 16, 2021 by admin

Knowing how to identify, treat, and prevent fungal diseases in your houseplants is essential for keeping your houseplants healthy and flourishing. Many fungal diseases are incredibly easy to avoid. Keeping your houseplants in areas that are frequently ventilated and making sure to not over-water your houseplants are just a couple of simple ways to steer clear of houseplant fungal diseases.

In this guide, you will find an overview of the 4 most common houseplant fungal diseases. You will learn how to identify, treat, and prevent basal stem rot, powdery mildew, Botrytis blight, and Anthracnose from destroying your houseplants.

Basal Stem Rot


Basal stem rot happens when plants are overwatered for a long time or if they are housed in a planter that does not drain excess water from the soil adequately. What essentially happens is that the plant rots from the roots up to the stems and leaves.


Basal stem rot is easy to identify because it begins in the roots of the plant and then moves up to the stems and eventually the leaves. Roots can turn mushy and brown instead of being white and firm. The browning of the plant then moves up along the stems and eventually to the leaves of the plant.


Unfortunately, basal stem rot is difficult to eradicate once it has already begun in a houseplant. Unless you are able to save and transplant a portion of the plant’s still-healthy stem and leaves to a new and better-draining planter, it is best to just throw out the whole plant.


Luckily, basal stem rot is pretty easy to prevent. Make sure you water your plants consistently and never over-water them. Check the soil of the plant occasionally to see if it is excessively wet or if there appear to be any issues with the plant’s roots.

Use only well-draining planters and make sure the soil is not too compact. If you accidentally over-water your plant, make sure the planter is able to drain the excess water adequately. Keep the plant in a ventilated room that is not too humid.

Powdery Mildew


Powdery mildew is most often caused by a number of environmental factors in your home. Typically this disease crops up when temperatures are low (less than 70 degrees Fahrenheit) and humidity and/or soil moisture are high. Overcrowding your houseplants can also cause powdery mildew.


Just like its name implies, powdery mildew is a white powdery substance that appears on the leaves of infected houseplants. The powder often shows up in the shape of little round rings that can grow and merge together.


Treatment of powdery mildew is relatively simple, and this is not a particularly threatening disease for houseplants. Start by making sure plants are not clustered tightly together in order to ensure the powdery mildew does not spread from the original infected plant to its neighbors.


Change the environmental factors contributing to the occurrence of powdery mildew. Keep the temperature above 70 degrees Fahrenheit and make sure the humidity is not too high. Circulate fresh air through the room where the plant is kept.

Finally, check to make sure the plant is in a well-drained planter and that there aren’t fallen leaves from the plant crowding the soil at the base of the plant. Be careful not to over-water the plant.

Botrytis Blight (Grey Mold)


Botrytis blight, or grey mold, is a type of fungus that feeds off dead plant material and can spread to healthy parts of the plant or to other plants very easily.

Botrytis spreads by releasing its spores into the air, which means extra caution is required when handling this houseplant disease to keep it from rapidly spreading to other parts of the plant or to nearby houseplants.


Botrytis can be identified by the brown spots that it makes on fallen leaves of the plant or on leaves and flowers still attached to the plant. Sometimes the brown spots look similar to a bulls-eye pattern. The spots will grow and merge together if not properly treated.

Botrytis blight most commonly affects flowering plants and can kill bulb flowers like tulips before they even have a chance to bloom.


Carefully remove dead plant debris from the planter. Try not to disturb the dead matter too much or the disease could easily spread. Trim off the affected areas of the plant using sterilized tools. In severe cases, you may need to use a plant-safe fungicide to get rid of the Botrytis and save your houseplant.


Clean dead leaves and debris from the base of your plant. Give your plants some space from each other; don’t crowd or cluster plants together. Ventilate the area where the plants live and make sure to not over-water the plants.



Like most of the fungal diseases that have been discussed so far, Anthracnose is caused by poor environmental conditions around the houseplant. Injury to the plant can also be the starting point of anthracnose infection because the mold spores will prey on injured plant tissue.


Anthracnose is easy to identify because of its distinct symptoms. At first, the tips of the leaves of the infected houseplant will turn yellow and begin to wilt. Next, the yellow color spreads up the leaf, more wilting occurs, and eventually, the tip of the leaf turns brown.

Left untreated, this disease could kill the plant by spreading from the tips of the leaves all the way down to the roots.


“Nip it in the bud”; perhaps there is some truth to the old saying. To stop Anthracnose from killing your plant, you must remove dead or dying leaves immediately. Cut the leaf off well below the point where the leaf is yellowing or browning and wilting.

Avoid spraying or misting plants infected with Anthracnose as this could cause the disease to spread more quickly through the leaves of the plant.


Like most of the other diseases that have been discussed so far, Anthracnose is easy to avoid. Simply make sure your plants have healthy environmental conditions. Remove dead or dying leaves and don’t let dead plant debris sit at the base of the plant for a long time.

Related Questions:

How Do I Get Rid Of Mold On My Houseplants?

There are many plant-safe fungicide products available that can be used in houseplants to get rid of different kinds of mold. Check your local home and garden store for plant-safe fungicides.

What Non-Fungal Diseases Are Common In Houseplants?

There are many non-fungal diseases that can affect houseplants. Most of the time these diseases are caused by poor environmental conditions, soil with improper mixes of fertilizer, and over-or under-watering of houseplants.

Common non-fungal plant illnesses include wilting, yellowing of the plant, bud drop, yellowing and browning of lower leaves, and cold water spots.

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