Q. How can I treat fungus gnats in my houseplants?
These common insects lay their eggs in the soil. When they hatch, the larvae live in the soil and eat the plant roots until they become adults. Fungus gnats are usually a sign of over-watering because they thrive in moist soil environments. Probably the simplest way to control or eliminate the gnats is to allow the soil to dry out thoroughly between watering. Reduce watering houseplants to not more than every 7-10 days. Depending on the plant, you could even go 2 weeks between watering. Basically try to go as long as possible between watering without causing more stress to the plants. By letting the soil dry out, you reduce the number of eggs that will hatch and, over time, hopefully eliminate the problem. You can also buy yellow sticky cards to catch the adults flying around.
Check out this fact sheet from Colorado State University for more information.
For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service