The Plant Care Habits That Are Secretly Attracting Gnats

I'll admit something a little embarrassing. After years of running uBloomd and telling customers how to keep fungus gnats away, I went and checked my own plant shelf last week and found gnats hovering over three separate pots.

So I did what any founder with a slightly bruised ego would do. I went through every plant, every watering habit, every bag of soil in my house, and worked out exactly where I'd gone wrong. Turns out most of it comes down to a handful of very normal, very common habits that most plant lovers do without a second thought, myself included.

If you've been noticing more fungus gnats around your indoor plants this spring, there's a good chance one of these is the reason why.

First, a Quick Fungus Gnat Refresher

Fungus gnats (sometimes called midgies, sciarid flies, or soil gnats depending where you grew up) are small, dark flies that hover just above the soil surface of houseplants. The flying adults are annoying but mostly harmless. The real damage happens underground.

A single female fungus gnat can lay up to 150 eggs in her short lifetime, usually just seven to ten days. Those eggs hatch into larvae that live in the top few centimetres of damp soil, feeding on organic matter, fungi, and, in bad infestations, tender plant roots. The full lifecycle from egg to adult takes around three to four weeks, which means once they've established themselves, you're not dealing with a handful of gnats, you're dealing with overlapping generations breeding continuously.

Spring makes this worse. Warmer temperatures speed up the entire lifecycle, and increased watering (which most of us naturally do as plants come out of winter dormancy) creates exactly the damp, organic-rich environment fungus gnats need to thrive.

Bad Habits:

1. Watering on a schedule instead of checking the soil

This was my biggest one. I'd gotten into the habit of watering every Sunday, regardless of how the soil actually felt. Fungus gnat larvae need consistently moist soil to survive, if the top layer never gets the chance to dry out, you're maintaining ideal breeding conditions permanently, whether your plant needs the water or not.

The fix: check the top two to three centimetres of soil with your finger before watering. If it's still damp, wait. Most common houseplants (pothos, monstera, philodendron, peace lilies included) are far more tolerant of slightly dry soil than they are of constantly wet soil.

2. Soil mixes that hold too much moisture

Standard potting mixes, especially ones heavy in peat moss, hold moisture for far longer than most plants actually need. That extended damp period is prime real estate for fungus gnat eggs and larvae.

The fix: mix in perlite, coarse sand, or orchid bark to improve drainage, particularly for plants that don't need constant moisture. A mix that dries out evenly, rather than staying soggy at the bottom of the pot, makes the environment far less hospitable.

3. Saucers left sitting with water in them

This one's sneaky because it feels responsible, catching excess water so it doesn't damage furniture or flooring. But standing water in a saucer keeps the base of the soil consistently wet from below, even if the surface looks dry.

The fix: empty saucers within thirty minutes of watering. If you're prone to forgetting, elevate pots slightly on small risers or cachepots with drainage gaps so water doesn't pool directly against the base.

4. Reusing old soil without checking it first

If you've repotted using soil that's been sitting in a bag or bin for a while, particularly if it's been kept somewhere humid, there's a real chance it already contains gnat eggs or larvae before your plant ever goes into it.

The fix: for new plants or repotting, use fresh, sealed soil where possible. If you're reusing soil, let it dry out completely and consider baking a small batch in the oven (yes, really) to kill off any eggs before use.

5. Overpotting

Putting a plant into a pot that's too large for its root system means there's more unused, unclaimed soil sitting around the roots, staying wet for longer because there's no root mass to absorb the moisture. It's one of the most overlooked contributors to a gnat problem.

The fix: size pots to the plant, not the other way around. A pot that's only slightly larger than the current root ball will dry out far more evenly than one with several centimetres of empty soil on every side.

What to Do If You Already Have Them

Fixing the habits above stops new gnats from establishing themselves, but it won't do much for the ones already living in your soil right now. That's where sticky traps come in, they catch the adult flies before they can lay the next generation of eggs, breaking the breeding cycle while you work on drying things out and adjusting your watering routine.

A combination of both, better watering habits and traps to catch what's already there, is the fastest way back to a gnat-free plant shelf. No sprays, no strong smells, just a quiet, steady clean-up while your plants keep doing their thing.

Spring's here, the gnats know it, and now, hopefully, so do you.

— Emily, Founder of uBloomd