In Your Backyard - Fungus Gnats

Growing a herb garden indoors, or any plants for that matter, doesn't keep them from having pest problems. Somehow insects find their way inside. Visible signs of small flies flitting between the leaves when you put your hands near the herbs means that fungus gnats have found your planters. Overwatering and soil contamination are the main reasons that the little pests feel comfortable.  They lay their eggs in the wet soil and when they hatch, the decomposition provides lots of food for them to thrive.  Once you see the flies, you need to get control quickly. If you are vigilant, you will see the flies before damage to your plants and roots occur.

What should you do? First, if its herbs and you want to use them in your cooking, you don't want to use any insecticides that will contaminate the plants.  Make sure your plants are in the right location where they get enough sunlight and good air movement. Stop overwatering and only water soil when its perfectly dry to the touch. Don't let the water sit in the pot liners.  Try using the yellow sticky boards that will collect them as they unknowingly get stuck when they fly close by. Change out the sticky boards when full and replace until they are gone.  You may even want to change the soil out to get rid of any larvae.


Darkwinged Fungus Gnats , Lycoriella spp. and Bradysia spp., Sciaridae,
Credit: Lance Osborner, University of Florida/MFREC