How do you get rid of gnats in houseplants?

Discussion in 'Houseplants' started by daisybeans, Aug 5, 2009.

  1. daisybeans

    daisybeans Hardy Maple

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    Our Admin Asst keeps our office green with beautiful plants of all kinds.... Currently though, they have GNATS and they are driving us crazy. We have been spraying with horticultural oil on the soil and leaves... they may be fewer for a day but they just keep coming back...

    Help... Soon... or she will start pitching the plants and they are too pretty....

    Anyone have a cure for gnats?

    Thanks...
     
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  3. toni

    toni Mistress of Garden Junque Staff Member Moderator Plants Contributor

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    Since the spraying didn't work, they are most likely living and breeding in the soil.
    Someone needs to take them home and repot them in fresh soil. Wash the old soil off the roots and give the plant itself a good bath before repotting.
     
  4. daisybeans

    daisybeans Hardy Maple

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    Well. That is kind of what she was afraid of hearing.... There are too many of them to take home... but I suppose we could accomplish this in the parking lot! With a Big Bucket of water. I'll help her if she's up for it.... it will go fast...

    Thanks Toni!
     
  5. Netty

    Netty Chaotic Gardener Plants Contributor

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    Daisybeans, I once heard that to catch the larva in the soil, you simply put a thick slice of raw potato on top of the soil. You will need to replace the potato daily I think. It's worth a try!
     



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  6. daisybeans

    daisybeans Hardy Maple

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    Ooh, thanks Netty... hadn't heard of that one.... We'll give it a try... can't hurt anything! Now, do I have some potatos to take in with me tomorrow....???? We've also heard that they are attracted to cider vinegar in a bowl in the area...
     
  7. stratsmom

    stratsmom Flower Fanatic

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    They are annoying little buggers aren't they? :twisted: I had to repot with fresh soil and that seemed to help the peace lilies in my bedroom.
     
  8. kuntrygal

    kuntrygal Texas Rose

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    DB, I had a problem with gnats in a couple of house plants and ended up throwing the plants away. Thinking the plants were gone, so were the gnats. Not so, even though plants were gone the flying gnats then proceeded to lay their eggs in the drains of the kitchen and bathrooms. I ended up calling an exterminator. He called them drain gnats and half-way used the chemical called for (he did refund my money since he didn't take care of the problem!!). It is called Drain-Gel and you buy it from a chemical company. Anyway loooonnng story short, I had to buy two gallons of the Drain-Gel and treat all the drains every night after the drains were used for the last time, for 7-9 days. I thought I would never get rid of them. I have been free of them for about two months. I will never buy another house plant!!! :-x :twisted:

    You mentioned cider vinegar. During this time and even before I bought the Drain-Gel I had several small dishes sitting around the house with the cider vinegar(wow the house smelled good! :rolleyes: ). The longer it sat the more pungent it became and the more the gnats liked it. I would check the dishes each day and the count of drown gnats just kept going up :D . I placed the dishes near a window or a bright light which draws them to the bowls of vinegar.

    Maybe yours aren't as out of control as mine were!

    But since you aren't going to toss your plants, they must have the soil changed and roots washed, pots washed before ever putting back in the planters.

    Good luck! :p
     
  9. daisybeans

    daisybeans Hardy Maple

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    Who-boy... That sounds like an ordeal.... they are so darn persistent.... well, I'm glad they're gone now anyway, KG...

    There are a LOT of beautiful plants in our offices ... I hope our AA is up for repotting -- it would probably take a whole day ... but I think it would make her sad to pitch the plants ... Her name is BJ, she has an amazing green thumb, and takes good care of us AND our plants!

    I wonder where they came from to begin with. BJ thought they may have come in some inexpensive soil -- what do you guys think?
     
  10. kuntrygal

    kuntrygal Texas Rose

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    Yes they come in soil and when you buy the plants. If plants have been over watered the soil starts getting sour and the gnats love that enviroment. You can unknowingly buy a plant that has them and introduce it to exsiting plants and viola'.

    I hope you and BJ have an easier time eradicating the pests, than I did!
    Good luck to you. :p
     
  11. Sjoerd

    Sjoerd Mighty Oak

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    Wouldn't it be fun to order a couple of Dionaea muscipula (Venus Flytrap) plants and place them on the window sill near your plants. They are very inexpensive here, I do not know about there. They could earn their keep. ;)
     
  12. daisybeans

    daisybeans Hardy Maple

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    Wow, do you think that would work Sjoerd? Assuming I could find them. Anyway, BJ took them all home with her to wash the soil.... bless her heart.
     
  13. stratsmom

    stratsmom Flower Fanatic

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    Every time I've brought in a poinsettia I've brought in a new gnat family :smt019 Also, when Tamie gives me a plant I spray the dickens out of it because they are always infected :-o
     
  14. weeds n seeds

    weeds n seeds Seedling

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    Fungus gnats

    This may sound really "off the wall", but have found it works! Mix 1 cup of hydrogen peroxide in one gallon of water: let the mixture sit..uncapped..over night, then drench soils of plants infected with the nasty things! Repeat application several days later, then periodically to keep them under control. The hydrogen peroxide does two things: "knocks" chlorine out of city water; causes an high oxygen level in soils that bugs can't tolerate but DOES NOT HURT the plants! (This information was found on the "Uses for Hydrogen Peroxide in Gardening" web site.)
     
  15. Christer Johansson

    Christer Johansson Seedling

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    I had problem before when I germinated cactus seeds, the gnat larva eat my tiny seedlings. But I found out if you top-dress with gravel in the pots there be no more gnats. They only lay eggs in the soil if they find organic material for the larva to eat, and the gravel fools them to think there are no organic material there. Works for me, anyway 8)
     
  16. JeffGibson007

    JeffGibson007 New Seed

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    I have tried following methods and these work like a charm:
    1. We have used Dish soap with luke warm water it works superbly against gnats.
    2. We have also used apple cider vinegar trap against them and they are awesome to kill the adult gnats.
    3. Gnats hate the smell of Holy Basil, Lavender, Citronella oil so you could use them for keeping gnats away.


    Moderator's note: removed website link, see point 1.1 of community rules
     
    Last edited by a moderator: Sep 15, 2015

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