Often confused for fruit flies, fungus gnats are one of the most common houseplant pests.
These little guys seek out moist soil, so allowing your houseplants to dry out a bit between waterings can slow down or stop an infestation. Be especially cautious during winter months as plants can take longer to dry out.
Adult fungus gnats don’t damage plants or bite people but larvae can damage roots and stunt plant growth if the infestation is allowed to continue.
To eliminate them, both the larvae in the soil as well as the adult flies need to be treated. Simply dealing with the adults won't stop the eggs from hatching.
Here's what you should do:
1. Isolate the affected plant. We don't want these suckers spreading.
2. Allow your plant to dry out completely.
3. Grab yourself a sticky trap to trap the adult gnats
4. Mix up a neem oil solution and soak the soil about once a week (or as long as it takes for it to dry completely) until you stop seeing gnats.
Unlike many other pesticides, it won't harm your pets or kill beneficial insects like earthworms.