Pest tips: Getting rid of Fungus Gnats

Pest tips: Getting rid of Fungus Gnats

Jan 29 , 2020

Fungus gnats got you heckin’ concerned? Well fear not plant fronds, part 2 of my pest treatment series will cover off these annoying creeps! First, a quick caveat. There’s loads of effective ways to treat gnats but I can’t cover them all. So I’m going to explain my method of choice, and why it works.

Gnats aka those black buzzing creatures that fly into your mouth are, by far, the most common pest for house plant owners. The bane of every plant Facebook group as it’s the most commonly asked question. They’re often the first issue that new plant owners face, and can be the cause of great distress so if my post does nothing else today for gnat-afflicted readers, please know that your plants will be fine and this is very fixable. You’ll find them buzzing around your plants, running on the surface of soil, and living in soil in larvae form. You’ll commonly read that they do best in damp soil, which is absolutely true, as this is their optimal breeding environment but don’t confuse this with thinking wet soil creates gnats (which I read A LOT). Gnats create gnats. They do not sporadically appear from soil. They enter your home via other plants or soil & breed like crazy. Because they exist in two forms - baby gnats or larvae live in soil, and adults fly around - my treatment method addresses killing both forms for maximum efficiency.

So! To treat them, the steps are:

  1. Do not panic. They are more annoying than they are harmful to your plants
  2. Seriously, don’t panic! If you’re diligent about treating them, you’ll win the war in no time
  3. Get yourself some neem oil, and mix it with water per packet instructions for a soil soak. This will be applied to the soil to kill the larvae that are living there, so you can eradicate them before they hatch. This treatment addresses one stage of their lifecycle
  4. Deeply water the soil of every plant you own (until water runs out the base). Even the ones in other rooms. Every plant. Because the adults fly, it’s very easy for them to spread across your collection and lay a few eggs in the soil of all your pots. They are crazy efficient at reproducing, so if you want to get rid of them quickly, a blast treatment is the way to go. Plus neem is organic, won’t harm your plants, and is a great preventative treatment to keep gnats and other pests at bay
  5. Repeat a week later. The repeat treatment is necessary if you’re at infestation levels but if you only have low levels you can skip it if you really want to. By the way, if you have plants in non-draining pots, water until they’re full and then pour the water out after a minute to drain them
  6. Get yourself some yellow sticky traps (Bunnings or eBay). The yellow colour attracts gnats, which land on the strips and then get stuck, and dye. Cut them up into tiny squares and lay one or two on the soil of every plant. This interrupts their breeding cycle, as rather than laying eggs in the soil (which is what they were about to do), it instead stops them dead. Literally. I leave these traps up year round to keep gnats at bay, and if you’re careful about how you place them, you can barely see them
  7. That’s it! You may find yourself repeating this from time to time, so to keep them at bay always put new plants in quarantine for a week when you bring them home so you can treat any hitchhiking pests before introducing them to your whole collection

Now, this can be a labour intensive process especially if you live in a small space, don’t have a backyard or balcony area, and/or have a large collection. Which is why spot treatment can be appealing. But if you can eke out an hour (or do it in batches across a few days), you will save yourself time in the long run from repeated treatment. And save your sanity too as they’re goddamn annoying. If you’re super time poor, it can help to let the soil of your plants completely dry out as this will kill larvae as they like damp soil as their habitat.

Links to other pest tips can be found below:

Tips on understanding pests

Tips on spider mites

Tips on mealybugs

Tips on aphids

Tips on pest prevention

Plus more to come