How to treat and prevent fungus gnats

How to treat and prevent fungus gnats

Each year us plant parents look forward to the spring and summer months when the sun will bathe our plants in much missed sunlight. We’re excited to see them grow; how many new leaves will they give us this growing season? What we’re not looking forward to: the dreaded fungus gnats. These pesky flies can infest your plants all year round, but you’ll find them much more prevalent through the warmer months as they thrive in a humid environment.

Though they’re a nuisance, they rarely cause any harm to your plants. But that doesn’t mean you want them buzzing around you or your plants. Fear not! We’ll give you some tips on how to treat and prevent fungus gnats from ruining your perfect planty summer.


  1. First you’ll want to take care of the adult population. We recommend sticky traps to reduce their numbers. Make sure they’re yellow as the gnats are attracted to this colour.
  2. Next you’ll want to treat the soil. You can do this using a mix of mild soap, neem oil, and water. A tsp of each per 1 litre of water will do. Then spray this on the soil. Make sure the top layer of soil is thoroughly covered. Neem oil is a natural pesticide and works great at getting rid of all houseplant pests. After a few treatments you should start to see results.
  3. If the gnats are truly persistent you can change your plant’s soil. Remove all the soil, including from around the roots (and give those a wash too) to make sure all the eggs and larvae have been removed. Make sure you use specialised houseplant soil to repot with as this will be sterile, so you won’t have to worry about any pests being introduced to your plant.


Ridding yourself of fungus gnats is all well and good, but how do you stop them from coming back? We recommend bottom watering for all of your plants (where possible) and avoid watering too frequently. Gnats can only lay their eggs in wet, humid conditions, so by bottom watering and letting your plants dry out, you avoid the top few inches of soil from becoming damp. This means the gnats will have no where to lay their eggs and you’ll be rid of them for good.


Now that you’ve said bye bye to those fungus gnats, you and your plants are free to enjoy a summer of fun. Happy growing!