How to Get Rid of Fungus Gnats in My Plants

Fungus gnats tend to reside in a plant's soil.

A houseplant encircled in tiny flying bugs is suffering from an infestation of fungus gnats. Fungus gnats are attracted to moist, organic matter, like potting soil, and will live off of and lay eggs in the dirt. Although some species of this tiny insect are harmless, others actually feed on the roots of plants, which can cause significant damage. Removing the pesky bugs is beneficial for your environment and easy to do.

Things You'll Need

• Sticky traps
• Insecticides

Instructions

1. Place sticky traps on top of the soil of the plant. Sticky trips are basically flat pieces of material that are covered with an adhesive that contains pheromones, which attract the bugs. The adhesive traps the flies when they come in contact with them and won't let go. Throw the trap away when it is full. All of the fungus gnats in the soil should eventually come in contact with the traps and perish.

2. Stop watering your plant. Allow the soil to dry out to make the conditions less than favorable for the fungus gnats and so they search for a new place to live. Many plants can go for a week or two without receiving water, which is usually enough time for the soil to dry out and the bugs to leave; however, the length of time your plant can go without water is specific to your particular plant.

3. Spray the plant and soil with an insecticide that contains pyrethrin. The insecticide should take care of the gnats and prevent them from returning. Most products of this nature are sprayed directly to the plant and the soil; however, read the directions on your particular product to know for sure.

Tips & Warnings

• Only use containers with drainage holes in their bottoms. The holes prevent soil from becoming too moist, attracting the gnats as well as root rot.

• Seal any cracks around your windows and replace screens that have holes in them to prevent the fungus gnats from getting into your home and infiltrating your plants. Make the repairs before August; the time in which the gnats seem to come indoors.

• Sticky traps and insecticides are typically available at garden centers.

References

• Oregon State University Extension; Do Your Potted Plants Have Fungus Gnats?; Carol Savonen
• Guide to Houseplants.com: Fungus Gnats: How to Identify and Get Rid of These House Plant Pests