Fungus gnats from soggy soil
Tiny black flies darting around the pot are fungus gnats, a sign the soil is staying too wet.
Diagnosis
Fungus gnats from soggy soil
What's happening
Fungus gnats lay their eggs in damp topsoil, and their larvae feed on the organic matter and tender young roots and bulbs. They're harmless to people but signal that the mix is staying wetter than Purple Shamrock likes, and heavy larvae populations can nibble at the very bulbs the plant depends on.
How to fix it
Let the top inch or two of soil dry out fully between waterings — gnats can't breed in dry topsoil, so this alone breaks the cycle. Water from the bottom for a while to keep the surface dry, and cover the soil with a thin layer of coarse grit or sand. Yellow sticky traps catch the adults, and switching to a fast-draining mix in a pot with good drainage prevents a repeat.
What fixes it
- Pots with drainage holes — Repotting into a pot with real drainage keeps the topsoil from staying soggy, which is what fungus gnats need to breed.
If that doesn't fix it
This is general guidance based on common symptoms; individual plants vary.
Read the full Purple Shamrock care guide →
Reviewed June 2026 · how we check this