Fungus gnats are an annoying pest houseplant owners are likely familiar with. These tiny flying insects are mostly a nuisance but can also be damaging to your plants in large numbers. There are many methods for getting rid of fungus gnats, but one of the best defenses is to prevent them entirely. Here are some of the best ways you can prevent fungus gnats from appearing in your plants:
As their name might suggest, fungus gnats thrive on the fungus growing in damp soil. They also prefer moist soil for laying their eggs. Therefore, a simple way to prevent them from taking up residence in your plants is to keep the top layer of soil dry. Try to go as long as possible between waterings if the plant allows, and consider switching to bottom-watering as an extra help.
Usually you'll find gnats around the top of the pot, but they can also end up in the drainage holes at the bottom. If they lay eggs in the drainage holes, you'll still have a problem even after completely replacing the soil in a pot.
Two things you can do to combat this are to wash and cover the drainage holes. Wash the pot thoroughly with soap and water before use, and use a coffee filter or another porous barrier inside the hole. Moisture can still drain out, but it will keep the gnats at bay--and prevent soil leakage.
You can also protect the top layer of soil from fungus gnats. One way is by covering the top of the soil with a thin layer of sand. The fungus gnats won't be able to penetrate through the sand to lay eggs in the soil beneath. While this method may not work perfectly on its own, it's an excellent way to double your defenses.
Fungus gnats are aggravating, but with the right tools and methods you can control and even eradicate them. Keep these strategies in mind when caring for your plants to keep them healthy and pest-free.