Fungus Gnats

The most common houseplant pests are fungus gnats, spider mites, mealybugs, thrips, and scale insects. Each one hides differently, causes different damage, and responds to a different first treatment. The fastest path to solving any of them is figuring out where the problem is showing up first, not reaching for a product. If nothing is moving and the pattern looks more like spreading spots, mildew, rot, or wilt, switch to the houseplant diseases guide before treating for insects. ...

You pull back the leaves, glance at the soil, and see something moving. Something tiny. Something that was definitely not there last week. Before you do anything, take a breath. Most tiny bugs in houseplant soil are either harmless or very fixable once you know what you are actually dealing with. The problem is that most people skip the identification step and reach for whatever spray or drench they have on hand. And the wrong treatment either does nothing, or stresses the plant while the real problem continues underground. ...

Hydrogen Peroxide for Plants: How to Use It Safely You have tiny flies circling your favourite plant, or you just noticed the roots looked off during a repot. Before you buy anything special, check your medicine cabinet. There is a good chance the answer is already there. Hydrogen peroxide is one of those quietly useful tools that experienced growers reach for early, not as a magic fix, but as a simple, low-cost way to deal with fungus gnats, root rot, and contaminated soil before things spiral further. It is cheap, widely available, leaves no chemical residue, and works fast. ...

By KnowYourPlant Editorial Team, updated June 24, 2026. This version keeps the guide aligned with extension and IPM guidance reviewed for the June 18, 2026 evidence refresh. Start Here if You Need the Gnats Down Fast If you are standing over the pot right now and just want the first three moves, do these before you try anything fancy: Put a yellow sticky trap in every suspect pot so you can see which container is actually feeding the outbreak. Let the top 1 to 2 inches of mix dry as much as the plant safely allows, then empty every saucer, cachepot, or reservoir holding leftover water. If adults return after the next watering, add a labeled larval treatment such as BTI or beneficial nematodes and focus on the wettest source pots first. If the plant is a seedling, fresh cutting, or already recovering from root stress, keep the dry-down gentler and lean harder on monitoring plus larval control. ...