Common Mistakes đŸ€”

Rethinking the 3 Most Common Fungus Gnat “Fixes”

A lot of plant care advice gets passed along like folklore—well-meaning tips repeated over and over without anyone stopping to question if they actually work. No one’s trying to mislead you; we all just want to help. But sometimes, there are better solutions.


❌1. Rocks, Gravel, Moss, or Sand as Top-Dressing

These might seem like they’d block gnats, but they don’t. Moisture still lingers beneath, and pests can still reach the soil—especially through drainage holes. Top layers can also trap mold, fungus, or other pests, hiding them until they become a bigger problem. Some of these materials are pricey, messy during re-potting, and ultimately ineffective for gnat control.


❌2. Sticky Traps Alone

Sticky traps feel satisfying—you can see the adult gnats you’ve caught. But they’re only part of the solution. Plenty of gnats avoid the traps, and the ones that do get caught don’t stop the others from laying eggs. Without addressing larvae in the soil, the cycle just continues.


❌3. Predatory Insects and Carnivorous Plants

These can help, but they’re often expensive and not always practical indoors. Carnivorous plants mostly catch adults within a small range, and beneficial insects—like nematodes—only work where they’re applied. Nematodes are sold in large packs meant for huge areas, can’t be stored after opening, and die once the gnats are gone (meaning you’ll need to repurchase). They also require consistently damp soil, which isn’t ideal for most plants and can even encourage more gnats.


Understanding the Real Cause

Fungus gnats lay eggs in moist soil or decaying matter. Overwatering is one of the biggest culprits, but gnats can also arrive with new plants, fresh potting mix, or simply fly in from outside.


A Simple, Effective Routine to Get Rid of Fungus Gnats for Good

  1. ✅ Use BTI Bits or Dunks in Your Watering Routine
    BTI (Bacillus thuringiensis subspecies israelensis) is a natural soil bacterium that kills fungus gnat larvae, mosquitoes, and blackflies—without harming people, pets, pollinators, plants, or fertilizers. Steep ÂŒ dunk or 1 tablespoon of bits per gallon of water for 1-24 hours before first use. Keep the container topped up and refresh the BTI every 30–60 days.
  2.  ✅ Diatomaceous Earth (DE)
    A natural, non-chemical way to damage soft-bodied insects. Only works when completely dry—mix into the soil or leave it for further protection once gnats are gone.
  3.  ✅ Yellow Sticky Traps
    Place one upright in each pot to capture flying adults. This helps reduce breeding while BTI takes care of the larvae. You can stop using them once your gnat population is under control.
  4.  ✅ Dry Out the Soil Between Waterings
    Most plants (other than the most delicate tropicals) prefer their soil to dry out a bit between waterings. Bottom-watering after your initial treatments can help prevent re-infestations.
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