Fungus Gnats in Houseplants

Have you ever noticed small flying bugs around your plants? Chances are, they are fungus gnats!


What is a Fungus Gnat?

Fungus gnats are small soft bodied insects that often inhabit houseplants.  They are dark bodied and have long legs and wings.  Fungus gnats spend a portion of their life in the soil eating organic matter and plant roots.  They spend the rest of their life above soil–flying around annoying plant lovers!  Although not harmful to plants in small numbers, fungus gnats are a nuisance.  In large populations fungus gnats can injure plants, especially small plants and seedlings.  Fungus gnats can even cause plant death when their population is large.


How to Control Fungus Gnats

Fungus gnats thrive in moist conditions where a lot of organic matter is present.  Monitor your watering and do your best to let plants dry out between waterings.  Choose potting mixes that have high porosity to encourage water drainage.  To gain more immediate control use: 


Yellow Sticky Traps 

Yellow sticky traps are commonly used to control flying adults; however, sticky traps alone will not contribute to overall reduction in fungus gnat population.  Generally, sticky traps are used to monitor population growth or decline.


Predatory Nematode 

Predatory nematode species Steinernema spp. and Heterorhabditis spp. prey on a variety of insect larvae in the soil, including fungus gnat larvae.  Predatory nematodes are relatively inexpensive, people and pets safe and very effective at reducing fungus gnat populations.


Mosquito Bits 

Mosquito bits are a pesticide made from a naturally occurring bacterial larvicide that is deadly to both mosquitos and fungus gnats.  Use mosquito bits by mixing 1 tablespoon per quart of water.  Let them rest for 30 minutes to make a ‘Mosquito Bit Tea.’  Apply this tea to your plants as normal.  Repeat this process for 3 weeks or add it into your regular watering regime.  Mosquito bits are people and pet safe. 

Recommended Posts

No comment yet, add your voice below!

Add a Comment

Your email address will not be published. Required fields are marked *