Identify the insects and check the mix first. Fungus gnats favour damp organic media. Sticky cards monitor and catch some adults; adjust watering without ignoring the plant’s own needs.
First look at where the flies gather
Adult fungus gnats are small, dark flies often seen near potting mix; their larvae live in damp media. Fruit flies near food and whiteflies around leaves may also be described as tiny flies, but need different responses.
Use a magnifier to look at appearance and behaviour, or seek help from a local horticultural extension or reliable plant diagnostic service. “Tiny black fly” alone is not a certain identification.
Check the mix and watering habits
Fungus gnats are often associated with damp, organic-rich media. If the plant tolerates it, let the mix reach the drying level appropriate for that species between waterings. Do not keep a moisture-loving plant excessively dry just to deter gnats.
Check drainage holes, saucers and cover pots, and empty standing water. Remove decaying fallen leaves. If the mix is badly deteriorated or infested, consider fresh mix at an appropriate time.
Use sticky cards to monitor adults
Place a yellow sticky card near the pot and check the insects caught over time. It can catch some adults, but it does not by itself eliminate larvae in the mix; address the moisture and breeding conditions too.
Use the card as directed and keep it away from children and pets. Do not assume every insect caught is a fungus gnat.
What if they keep returning?
Adults and larvae are at different life stages, so keep monitoring as conditions improve. Do not repeatedly soak the pot because a few flies remain after a day or two. Seek local horticultural advice for a severe or uncertain problem.
If you choose a larval-control product, use only one locally permitted and labelled for the pest and indoor potted plants, following its directions. Do not pour alcohol, detergent or improvised mixtures into the mix.
Common questions
Are all tiny flies near plants fungus gnats?
No. Check appearance and where they gather; fruit flies and whiteflies need different responses.
Will a sticky card remove the whole infestation?
It mainly monitors and catches some adults; it does not deal with all larvae in the mix.
Should I stop watering completely?
No. Adjust to the plant’s needs, allowing suitable mixes to dry appropriately between waterings while avoiding standing water.