Pest Control

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. ...

You notice a faint dustiness on the leaves. Maybe some tiny yellow speckles, or a leaf that looks a little washed out. You lean in closer and see the faintest threads of webbing in the crook where the stem meets a leaf. That’s when you know: spider mites have found your plant. Knowing how to get rid of spider mites is one of the most useful things you can learn as a plant person, because these pests move fast and they don’t announce themselves loudly. The good news is that if you catch them early, they’re very manageable. And even if the infestation has gotten ahead of you, there’s still a clear path back. ...