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Controlling Houseplant Fruit Flies & Fungus Gnats Naturally

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Wondering how to get rid of fruit flies or fungus gnats?

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

Well, the first thing I try to determine is whether the pest is truly a fruit fly or is actually a fungus gnat? That’s because these buggers are similar, but they’re also quite different too!

And the second thing to remember is that spraying some ‘cide probably isn’t necessary (and should always be a last resort.)

Both pests are tiny and truly annoying.

Fruit flies tend to invade our kitchens. And they do this a lot during harvest season. But to get rid of fruit flies isn’t always easy.

Plus, sometimes they move into our houseplant soil along the way. But, more often than not, the problem is actually fungus gnats. That’s because these are more common all year. And they tend to really set up shop in house plants. (But, they may show up in your kitchen too.)

So annoying! But you can get rid of fruit flies and fungus gnats without spraying gunk from a bottle.

get rid of fruit flies fungus gnats with pebbles on soil in planter

Steps for how to get rid of fungus gnats…

If the problem does turn out to be an infestation of fungus gnats,  a few simple environmental and pesticide-free control options will probably help you avoid, control and get rid of the fruit fly lookalikes:

  • First, add a thin layer of pretty pebbles or gravel to the top of the potting soil in your indoor plant containers. That’s because fungus gnats lay eggs in the top layer of the soil and hatch from there. But they can’t do this in pebbles.
  • Next, Cclean your plant pot catch trays. Thanks because gunky catch trays can be egg-laying spots for fungus gnats.
  • Finally,  if your infestation is really bad, you may want to go ahead and insert some sticky traps in your cleaned up planter for a little while. This can help catch the ones that are already flying around. And it can help break the lifecycle of any future babies they’re planning.

Try these methods if you’re not sure which pest insect you’ve got:

  • Begin by inserting sticky traps into your houseplants.  These are inexpensive, pesticide free papers covered with a sticky material. So as the gnats and fruit flies buzz above your plant, they are attracted to the yellow color and smack to the sticky surface never to fly again.
  • Or, let your other plants eat your flying pests instead. That’s because simply growing carnivorous plants like sun dews (in the Drosera species) can help eradicate fruit flies and fungus gnats. Just be sure to place the meat-hungry plants very close the pest infestation. For instance, place a sundew in the center of a bowl of summer ripe tomatoes. Or, keep it growing near other houseplants.

Try these techniques if you only need to get rid of fruit flies…

We learned a fun fruit fly control method from our friend Brad. Not only is his technique easy, but it also uses up food scraps you might otherwise toss in the compost. Here’s how to get rid of fruit flies this way:

  • First, Grab a glass or jar, piece of clear cling wrap, rubber band, and piece of ripe fruit.
  • Next, drop fruit in jar.
  • Then, Tightly pull down clear wrap around the top of vessel. And wrap rubber band around rim of vessel.
  • Next, use a pin to poke several small holes through the top of the cling wrap. This way the the fruit fly can squeeze into the hole. But it will be very difficult for them to escape later.
  • Finally, put the glass in your fruit fly area.
  • Once several flies are in the glass, place the whole thing in the freezer. That should kill the flies. And you can set the intact trap back on the counter to catch more later.
  • Finally, empty it all once the fruit begins to really rot.
DIY fruit fly trap

Brad’s Gnat Death Trap (Photo courtesy: Brad Hole)

Additional suggestions after trying Brad’s great method:

  • Use a scrap of fruit like the peel from an apricot or the pit from a peach.
  • Be sure to poke really tiny holes in the cling wrap. Otherwise, they’ll just fly out again.

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55 comments on “Controlling Houseplant Fruit Flies & Fungus Gnats Naturally

  1. Bill on

    I have a question re: growing herbs indoors that have fungus gnats. If I put an inch of pebbles or sand at the top of the herb pots (tarragon, parsley, mint, rosemary, chives at the moment) does this weight on the topsoil hinder the herb developing and growing bigger? Also, once the sand/pebbles are there, do I continue to water from top at root level? Wouldn’t that just make wet sand for the gnats to enjoy? Watering from the bottom is difficult given my apartment situation and size of the pots. Thanks!

  2. Garden Mentors on

    Bill, it’s unlikely that a gravely layer as the top of your growing medium will hinder plant growth. Top watering should be fine. The gravel helps deter the gnats from laying eggs. A slightly larger grit than sand would be our preference. Good luck!

  3. L. Albright on

    Glo-sticks work really well especially if placed alongside a small night light in the bathroom. Requiring two AA batteries, the blue light they emit will also attract the gnats at night when placed alone near plants. I bought my Glo-sticks online. They will capture dozens of the beasties before you have to change the sticks (narrow tubes with very sticky clear glue).

  4. Toni on

    I used a spray with water, thyme eo, oregano eo and peppermint eo. Plus a drop of dawn. Filled it up with water and sprayed it on all my outside zucchini and sweet potato plants. I barely found the infestation today but I decided to throw out all the soil and grow bag. I’m not sure if it is a soil gnat but I decided to try it. The essential oils are you g living brand. I have used the peppermint eo with water with success in the past.

  5. Elaine Cramer on

    I live in a small town and can’t find decorative gravel. Anything wrong with using vermiculite instead?

  6. Garden Mentors on

    We’ve never tried vermiculite & kind of doubt it will work. Even if you don’t choose to use our Amazon affiliate links in this post, there are many online retailers that will ship products to you. Good luck!

  7. L. R. on

    Fruit flies will breed in sink/tub drains & toilets. Pour a pot of boiling hot water down drains & toilets. This will kill any eggs. Also keep drains free of hair,etc. This also attracts the flies. When first noticed flies I put out containers of vinegar with a drop or two of Dawn Dish Soap, cover top of container with Saran Wrap. Use a toothpick to punch about 5-6 holes in the wrap. The flies will go into the holes, but can not get out.

  8. Kylie on

    I had a LOT of tiny flies around my plants, they only seem to like the plants they’re not in the kitchen or anywhere else, only the living room where my plants are… I’ve spent all night catching them and putting them out of the window but now I’ve googled and can see it’s probable that more will hatch! What a pain they are! Thanks so much for all of these tips, I will be trying to get my hands on some gravel and making sure I let my pots dry out a bit!

  9. Mary on

    I had mint stalks in a mason jar in my kitchen window and something ate every leaf! You can tell they were chewed! I have seen the fungus gnats in my house so now suppose they are the culprits. Mint is obviously NOT a deterrent. LOL I am definitely going to try some of these ideas.

  10. Andras on

    I tried using mint plants in my kitchen, for the wee gnats and it doesn’t work. I also put grit into my coir based compost and also sticky yellow traps(which do work for my houseplants). The bright yellow traps last for 3 months and they work very well. The gnats prefer damp compost too. After trying citrus based sprays near my pots, it has little affect.

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