Gnats in my plants, how do I get rid of them?

Ruth P. Hakulin
by Ruth P. Hakulin
I have a gardenia tree indoors and some African Violets that have tiny gnats flying around them. I let the soil dry out in all of the plants, watering just once a week.
  8 answers
  • Janet Pizaro Janet Pizaro on Mar 13, 2017

    You will need to repot the african violets in african violet soil,and the gardenia tree in the next size pot with fresh soil. The gardenia can be sprayed down with horticultural oil Next place bowls of apple cider vinegar covered with saran wrap and poke tiny holes in the top,this should trap the rest of the black fly.

  • Ruth P. Hakulin Ruth P. Hakulin on Mar 13, 2017

    I've used the Horticultural oil on the gardenia when I brought it in the house after summer because of scales on it. Worked perfect. It's not really black flies, but tiny gnats on the soil more in the gardenia soil than the african violets. But I'll try the vinegar and see it that helps.



  • Kauai Breeze Kauai Breeze on Mar 14, 2017

    Try spraying your gardenia with mild dish soap and water on the underside of the leaves. It kills most soft bodied insects without harming the plant. Great in the garden too. (Use only non-antibacterial soap!)

  • Janet Pizaro Janet Pizaro on Mar 14, 2017

    It is most likely fungus gnats.As stated earlier continue spraying the gardenia,however if that does not work you will have to change the soil as fungus gnats lay eggs in the soil making it very difficult to bring under control.

  • MaryAnn B MaryAnn B on Mar 16, 2017

    At a garden center you can find red sticky mats. The gnats fly to it and stick. See if that works and then follow up with horticultural oil, I use neem oil.

  • Dje4228473 Dje4228473 on Mar 18, 2017


  • Andrea Andrea on Jan 09, 2022

    I know this is an old post, but I feel the need to spread this tip when I see this question asked because I battled with these little Devils for MONTHS and nothing anyone suggested worked. Until I found out about gnatrol. It contains the bacteria called bacillus thuringiensis israelensis, which kills fungus gnat larvae and mosquito larvae - nothing else! It's organic and safe for pets and humans. You can get small packages of it on eBay, and there's also another brand of it that goes by the name Bactive - Bactive contains 40% of the bacteria bacillus thuringiensis israelensis, whereas gnatrol contains around 37%.

    If you want to buy a 1/2 pound of it on eBay then Bactive is cheaper(but still more potent). If you only want a few ounces you'll have to get gnatrol brand because bactive only sells in 1/2 lb and 1lb increments.

    All you have to do is add a teaspoon to a gallon of water and water all of your plants with it once a week for 3 weeks to stop the life cycle from progressing, and you will be gnat free, I promise you!

    I now water with it once a month as a preventative, because I cannot make myself risk another gnat infestation after the one I had over a year ago 😂

    I buy the 1/2lb bag because that's lasted a year without going bad and I don't see myself needing more than that for a year.

  • Johnavallance82 Johnavallance82 on Jul 31, 2023