How to Get Rid of Gnats in Plants in 7 Steps


Gnats are small, mosquito-like pests. These tiny insects not only become a nuisance inside the house but will eat away at your plants as well. From taking the necessary precautions to prevent gnats to ridding your home and plants of gnats should they arrive, these are the steps you need to take when it comes to how to get rid of gnats in plants.

You Won’t Instantly See Damage

While you may see signs of gnats (such as the larvae or the small black insects flying around plants), you won’t instantly see damage to the plant. Most of the damage gnats cause to plants isn’t externally visible. The damage occurs at the root level as larvae nurse off of the roots. This may lead to fungal development, which will cause additional damage to the plant.

Gnats are also a major annoyance inside the house, so by ridding the plants of these gnats, you’ll avoid potential plant damage and cut down on the nuisance.

1. Examine the Plant

When selecting plants at the nursery, make sure to carefully inspect the plant for gnats and gnat larvae. One of the biggest culprits to gnats coming into your house is when purchasing. Nurseries often overwater plants and don’t adjust the amount of water given to different kinds of plants. Due to this, there’s a greater chance of gnats showing up in nursery plants.

2. Repot Plants

You may decide to repot plants upon bringing the plants home. Should you do this you’ll want to use a new potting mixture. The new potting mixture will ensure you do not spread the gnats to other potted plants in and around the house.

3. Watch Your Moisture

Gnats love excess moisture. The insects lay larva in moisture-rich soil. In order to avoid gnats in the first place, you need to avoid overwatering the plants. It’s best to allow the soil to dry before watering again. You also want to take care of any drainage trays under potted plants and clean out the moisture build up here as well. As long as you do this, you likely will avoid gnats altogether.

One way to help avoid over saturation of the plant while making sure the plant still receives the necessary water is to water the plant from the bottom. Fungus gnats will lay larvae within the top inch or so of the potting soil. However, if water from the bottom, the plant’s root system will receive the necessary moisture without it reaching the top layer of soil. This way, you’ll avoid the development of most fungus gnats. Allow the plant soil to absorb the water in the bottom drip tray for around 30 minutes. After that, pour the excess water out.

4. Use Sticky Stakes

sticky trap for gnats

Sticky stakes will not kill of larvae, but this is a good way to rid houseplants of gnats if you’re just discovering the gnats. Sticky stakes are yellow sticky traps you’ll insert into the soil. Make sure you don’t let the plant touch the traps though. It’s non-toxic but can cause some growth problems if the plant sticks to it.

The gnats will land on the sticky stake and die off. When it comes to how to get rid of gnats in plants, this is one of the better courses of action regarding adult gnats. By killing the adult gnats you’ll reduce the number of larvae to deal with.

5. Use Pest Control Products

There’s no need to apply harsh chemicals to your plants. In fact, you can create organic products at home in order to rid the plants of gnats. There are organic insecticidal sops you can pick up at the local nursery, although you can also make the pest control product at home.

To do this, mix a mild liquid soap (something organic is always preferred, such as Seventh Generation or other, similar products) with water so you have a soapy mixture. It’s important to use a mild soap as the harsher cleaners may kill or damage the plant’s root system, which will affect the plant itself.

Apply the soapy organic mixture to the topsoil every few days. After a few applications, the gnats and gnat eggs will die off.

6. Prevent Future Gnats

When looking at how to get rid of gnats in plants, it’s important to also prevent future gnats. It’s an issue you don’t want to deal with again. The best way to do this is to apply a soil cover. To do this, remove the top inch of soil (this way you’ll remove any remaining gnat larvae) and replace it with sand, decorative moss or gravel. Gnats are unable to lay eggs within this material and as such, will not be able to survive in the house plants.

It is best to apply the soil cover to the plant after you know you have repotted it for the last time. Removing gravel and other, heavier covers becomes a bit more of a problem when constantly replanting the pot.

Soil covers are something you can use with both inside houseplants and plants around your property. When outside, you can still apply mulch around the plants if it’s a look you desire, but consider applying sand or gravel first. This way, the gnats are unable to plant under the mulch. This also helps reduce the possibility of additional plants, such as weeds or grass, from growing up around the plants.

7. Store Your Soil

When saving potting soil, do so in a sealed container. Leaving it open exposes it to possible gnat larvae prior to planting. So avoid needing to know how to get rid of gnats in plants by taking care of your soil ahead of time.

Final Thoughts

Gnats are tiny pests capable of turning into a big problem. The best way to avoid gnats is to remain proactive in your care of the plants. Should you identify the insects, it is necessary to take these tips on how to get rid of gnats in plants. As long as you do, you’ll avoid the development of gnats in the future while extending the life of your plants at the same time.

Jonathan E. Bass

Graduated from Middle Tennessee State University. I am currently a gardener. I have a small garden behind my house. I love it.

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