Controlling Fungus Gnats in Your Plants

Controlling Fungus Gnats in Your Plants  

Fungus gnats are a nuisance many gardeners and plant lovers have experienced. Fungus gnats occur when plants are overwatered, there is high levels of humidity, or there is sitting water. Although the gnats cause no harm to a plant, their larvae can harm plant roots and thus stunt a plant’s growth; they are nonetheless an unwanted pest. 


Gnats can be difficult to eradicate. They reproduce quickly and can move to other areas of your home like the sink drains or to food. Indoor plants especially, with their small enclosed containers, are susceptible to fungus gnats living in the soil when overwatered or if the soil has poor drainage. It can be more difficult to control fungus gnats in outdoor areas or containers, but there are steps that will help!


One of the easiest things you can do is decrease the amount of water plants are getting. It is best to let the soil of plants in pots, whether indoors or outdoors, almost completely dry out before watering again. This also helps reduce the risk of root rot and other fungal infections. If you need a little help in determining when your soil is dry, try using a popsicle stick and pushing it deeply into the soil, if it comes up with moisture or soil debris, the deeper soil is still wet and you can wait a few days before watering again. 

In order to kill fungus gnats that are flying around, use a mixture of one part water, two parts apple cider vinegar, and a few drops of dish soap. The gnats will be attracted to the apple cider vinegar, but get stuck in the soap. Do not shake or mix the soap in the mixture, avoiding soapy bubbles will make the trap more successful. 


Another helpful tip is to use aquarium rocks or decorative rocks over the surface of the soil, this will make it more difficult for gnats to enter or leave the soil. The ones trapped in the soil will die once the soil dries out. There are also gnat sticky traps that you can affix to your plants and in the surrounding areas, this can also be a good option for killing gnats as they enter and exit the soil. 


Fungus gnats can be an unwanted effect of too much moisture or water in a plant’s atmosphere. Getting to know your plants and their water needs will help you learn when and how much water to give them, and help you reduce the risk of gnats in your home and gardens!