• Featured Garden Help Articles

  • Featured Recipes

  • Get Garden Help by the Month

  • Get Garden Help by Topic

  • more info

Controlling Houseplant Fruit Flies & Fungus Gnats Naturally

November 05, 2008

As a garden consultant, I hear this question a lot: What do I spray to get rid of the fruit flies in my house plants?

The first thing I try to determine is whether the pest is truly a fruit fly or is actually a fungus gnat. They’re both tiny and truly annoying. Fruit flies tend to invade our kitchens, particularly during harvest season and sometimes they move into our houseplant soil along the way. I’ve posted ways to use carniverous plants in your kitchen to control them, and some of my readers have shared their methods as well in this post.

Sticky Stakes for Houseplants
If the problem does turn out to be an infestation of fungus gnats, the more likely culprit to live in houseplants, I steer people away from the pesticide aisle and suggest a few simple environmental and pesticide-free control options:

  • Add a thin layer of pebbles or gravel to the top of the potting soil in your indoor plant containers. Fungus gnats lay eggs in the top layer of the soil and hatch from there. They can’t do this in pebbles.
  • Clean your catch trays. Gunky catch trays can be egg-laying spots for fungus gnats.
  • Insert sticky traps into your houseplants. These are inexpensive, pesticide free papers covered with a sticky material. As the gnats buzz above your plant, they are attracted to the yellow color and smack to the sticky surface never to fly again.

If you’re not sure whether you’re dealing with fungus gnats or fruit flies, know this: Sticky traps attract both pests and may solve the problem regardless!

15 Comments

  1. Jack says:

    Really good suggestions for controlling fruit flies and fungus gnats. No one really want to use chemicals anymore as a solution.

  2. Ash says:

    Getting rid of fruit flies can seem like a daunting task for many people, but its easier than you think. We don’t want to have toxic solutions, however there are many products marketplace which offer a natural and non-toxic solution to combat fruit flies to prevent health issues.

  3. Rick Coash says:

    I am in an apartment and have an indoor composting bin with “red wiggler” worms. I need to know if there is an herb that I can but in my bin that will combat my infestation of fruit flies, that will not be toxic to the worms.

    Appreciatively,

    Rick Coash (co-ash)

  4. rhaglund says:

    Rick,

    Unfortunately I don’t have the perfect remedy for your fungus gnat infestation. You could trya tip another reader sent in: put a shallow dish filled with vinegar on the top layer of the worm bin (make sure it won’t spill). The flyin’ buggers may be attracted to it where they will drown. It won’t kill them all at once, but it may eventually break the life cycle. If my indoor bin ends up with a hatch, I set the bin outside where it is cold for a bit to freeze off the gnats. I may lose some worm productivity this way, and I have to take care not to freeze the entire bin, but it can help beat back the gnats, which like the warm. Not sure if you can do this in an apartment, but it’s an option.

    And, worst case, clear out the entire bin, sorting out your worms to keep. Spread the compost or recycle it outside the house. Clean your bin well and start over taking care to keep everything sealed and free of already-infested gnat goodies.

    Thanks for writing in & good luck!

  5. Flower Pot says:

    These are some really good ideas I haven’t run across before now…thanks.

  6. […] Is it a Fruit Fly or is it a Fungus Gnat? var a2a_config = a2a_config || {}; a2a_config.linkname="Great DIY Fruit Fly Control"; a2a_config.linkurl="http://www.gardenhelp.org/insects/ipm/pests/great-diy-fruit-fly-control/"; […]

  7. patty says:

    Would these gnats make the leaves on my plant curl or have what looks like tiny white dots in the veins of the leaves ?

  8. Patty,

    Fungus gnats can do damage, but I’m not familiar with them creating tiny what dots on leaf veins. Curling leaves and dotting sounds suspiciously like there was an insect with sucking mouth parts involved. Aphids, for instance, will suck the juices out of young leaves, leaving them damaged and curled as they mature. But, by the time the leaves are unfurled and curly, the aphids may be long gone. Insects like mites will suck the juices out of leaves leaving them looking speckled with white. So, not sure what’s causing your issue, but maybe this will help you dig a bit deeper. Thanks for writing in & good luck!

  9. Sarah says:

    I have had a problem with what I think is fruit fly. For 5 years they have invaded my house plants and in several cases caused them to die..
    The fly is living in the compost and the lavae is white an and if disturbed jumps about. I have tried jeyes fluid which seems to work on the adults and lavae but I cannot seem to get rid of them all.
    I am fed up with my plants dying, is there a remedy at all for this problem?

  10. In addition to what’s in this post, you could try putting gravel on the tops of the soil of your houseplants and allow that to remain somewhat dry. They can’t live in this environment. Sticky traps help break the cycle too.

  11. Christine says:

    Some very good suggestions. I am using the fly paper traps right now, one in my front room and the other in plant/sewing room. I also use apple cider vinegar in a medium size jar cover with plastic wrap make a few holes and set near plants, this actually works well. I am also going to try small decorative pebbles on the surface of my house plants..

  12. Shadow says:

    The sticky traps hardly caught any at all. They didnt bother.

  13. Try placing them closer to the swarms and you might have better luck Shadow.

  14. Linda says:

    I do a lot of canning and freezing of fruits in summer and fall and have lots of fruit flies. I solve the problem by placing a small dish or glass on the counter half full of apple cider vinegar with a couple drops of dishwashing liquid in it. The fruit flies get in that solution and drown. Has worked for me for years.

  15. Glad you have a solution for those suckers Linda!

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>