How to Kill the Little White Worms in Houseplant Pots

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Insecticides kill the adult gnats that produce the worms.

Indoor plants can be a gorgeous way to add some personality to your home decor, and caring for them properly is key to them looking their best. One important aspect of plant care is keeping the plants free of pests. You should become familiar with how to kill little white worms in houseplant pots and prevent them from coming back.


What Are These Worms?

The little white worms you might find in your houseplants' soil are not actually worms at all. They are the larvae of the fungus gnat, which is a small black fly that crawls around in plant soil or flies around your plant. These larvae and bugs are not only unsightly, but they can also feed on the organic matter in your houseplants' soil, including their roots. A heavy infestation can cause root damage over time.

On top of this, fungus gnats can quickly spread from houseplant to houseplant. If you notice that the soil of one of your plants has small white worms in it, it is important to deal with it quickly, or you can face a full-house infestation.


How to Remove Them

To treat fungus gnat larvae in your houseplant, first remove the top layers of gnat-infested soil. Place it in a bag, knot the bag and dispose of it. This may also be a good opportunity for you to fully repot your houseplant, removing the old soil and replacing it with fresh soil in a larger vessel to allow for better growth.

After a fungus gnat infestation, you should treat the soil with a mild insecticide that is suitable for indoor use. When mixed with water, castile soap is a great option, as it is safe on the skin and won't cause damage to your houseplants. Neem oil is another natural choice.


Your castile soap should be diluted with water (1 teaspoon per liter). For a neem oil preparation, mix 1 1/2 teaspoons of neem oil with 1 teaspoon of liquid soap and 1 liter of lukewarm water. Simply pour or spray a small amount of your chosen option on the top layer of your houseplant's soil.

Another option for removing fungus gnats from plants is an insecticide containing ​Bacillus thuringiensis. This can be applied to the soil of your affected houseplant and watered in, according to the manufacturer's directions on the product label.


How to Prevent Them

Once you have removed the fungus gnat larvae from your houseplant, there are certain steps you can take to ensure they don't come back. The most important is to minimize soil moisture. Make sure you are not overwatering your houseplant and allow the soil to fully dry out between waterings.

You can use a soil moisture meter if you are unsure of how often to water. Watering your plant from below or using a mister can help you resist the urge to overwater. Using different soil covers, such as gravel or sand, can also help keep the surface of your houseplants' soil feeling drier and thus less attractive to fungus gnats.


Always check on new plants before bringing them into your home to avoid bringing in new gnats. You should also fully inspect any indoor plants you are bringing back inside after a spell outdoors (during the summer, for example). A forceful spray of water around the base of the plant and top layer of soil should be enough to dislodge any new pests.



Annie Walton Doyle is a freelance writer based in Manchester, UK. Her work has appeared in The Huffington Post, The Daily Telegraph, Professional Photography Magazine, Bustle, Ravishly and more. When not writing, she enjoys pubs, knitting, nature and mysteries.