Fungus Gnat Control: How To Stop Their Control Of Your Plants, Gardens, and Greenhouses

January 14th, 2010 Posted in Flies & Gnats



The fungus gnat is a little fly that doesn’t really bother people or animals, but severely damages all kinds of plants. The fact they ruin gardens and greenhouses is what makes them one of the more pesky critters out there today. The fungus gnat got its name from the fact they primarily feed on fungus.


fungus gnat control



They also spread disease to your plants much like a fungus, which makes them one of the more deadly gnats in your garden or greenhouse. For that reason, it is extremely important to know as much as you can about the fungus gnat and how to rid yourself of their terror.

Ready to learn more?


Some Quick Facts About The Fungus Gnat

  • The fungus gnat ranges in size from 1.5-3.0mm in length

  • They’ve got long-legs and long antennas, as well as dark bodies and dusky black wings

  • Often feeding on fungi and dead plant materials, the fungus gnat eats almost any plant waste

  • The insects life cycle consists of growth from egg to larva to pupa, and finally to the last stage of adult

  • Once adults, the fungus gnats seek out fungi so that they can eat and then reproduce

  • Eggs are laid in moist wet soil by the female fungus gnat

  • The entire life cycle takes about a month until the gnat reaches full adulthood


Preventing The Fungus Gnat From Hurting Your Plants

So, the fungus gnat is attracted to fungus growing on or around your plants, right? Then that leaves the real question, what is causing the fungus in or around your plants? Overwatering is the underlying problem causing the attraction of the fungus gnat.


fungus gnat control



It is like laying a big buffet in your garden for the gnat. What happens is the overwatering causes there to be extra moisture making the environment prime for fungal growth. Fungus also hurts your plant by sucking as much of the nutrients out of the soil as possible, as well as hogging most of the water. Therefore, your plants may begin to die, which is also another source of food for the fungus gnat.

However, if you just avoid overwatering you can greatly help reduce the fungus gnat attacking your plants. Also, before bringing home a new plant inspect the soil for gnats or gnat eggs because if you introduce this new plant to your other plants you may infect them all with fungus gnats. These methods of damage control will greatly help you prevent further problems with fungus gnats.


Ridding Their Presence From Your Garden & Greenhouse

Like we’ve previously discussed, make sure to check the soil of any new plants you introduce because you risk contaminating your garden or greenhouse. If you already have fungus gnats in your garden then make sure to follow the above steps, but also construct a potato trap. Cut large chunks of potato into 1 inch square pieces.

Place them on the surface of your potting soil and the gnats and their larvae will eat the potato instead of your plants. This isn’t a 100% full-proof method, but successful enough to protect your already invaded garden or greenhouse. Another method to help rid them from your garden or greenhouse is through buying potting soil that drains well.


fungus gnat control



If the soil doesn’t hold liquid for too long, then you will drastically diminish the presence of the gnats. Buying predatory mites on the Internet, like the Hypoaspis miles, will also help to fight the fungus gnat. The predatory mites are so small to the human eye they can barely be seen. An adult mite can kill up to seven gnat larva per day making them an extremely effective method of removal.

Lastly, the most effective means of ridding yourself of gnats is through using EcoSMART’s organic pesticides. Our products are completely safe for the environment, thus your plants will remained unharmed, but the same can’t be said for the fungus gnat. Fungus gnat control is important because they can ruin your garden in a very short time. With that being said, our organic pesticides are safe and effective means of ridding yourself of the fungus gnat.




  1. 9 Comments | The First 1,000 to Comment (Starting 12/21/2009) Will Become EcoSMART Product Testers!

  2. By Santiago Martinez on Feb 12, 2010

    I have a gnat infection onn my indoor plants. I have tried ,go gnats. and other products and they kill but not all .
    I need something that will kill them completely

  3. By EcoSMART Brian on Feb 15, 2010

    Hello Santiago,

    Well, you are in luck! By using our Flying Insect Killer you can effectively and safely eliminate your gnat problems in your indoor plants and elsewhere.

    Check here for more info:

    http://www.ecosmart.com/shop/individual-products/flying-insect-killer.html

  4. By Stacy Rombach on Mar 9, 2010

    My houseplants are infested with the gnats and I have tried several products that have not worked. The problem gets worse in the Spring and I need something that will kill them before they kill my plants.

  5. By Mitch on Apr 6, 2010

    i’m growing my vegetables in buckets w/ Hydroton Clay rocks and I top feed from drip lines 24/7
    I always have fungus gnats and was wondering if spraying your flying insect killer on the surface of the clay rocks on top lightly would damage any of the roots or plants or effect the edibility of the vegetables ?
    I tried it and it seemed to do a great job of killing the gnats w/o adversely effecting the plants
    Is it safe to use on vegetables and other like types of plants at the root zone only

  6. By EcoSMART Brian on Apr 7, 2010

    Hello Mitch,

    Sorry to hear about your fungus gnat problems, but luckily our Flying Insect Killer is safe for use around roots, plants, and vegetables. It only targets receptors found in insects, leaving all other innocent bystanders unaffected.

    http://www.ecosmart.com/products/flying-insect-killer/

  7. By Jen on May 15, 2010

    My organic container garden is practically INFESTED with gnats! It drives me insane. I’ve been trying to cut back on watering but I live in Arizona and it’s starting to get hot. One soybean based repellent didn’t work, and I do the apple cider vinegar and dish soap method, but it only kills so many.

  8. By Jason on May 25, 2010

    I got some organic soil from home depot and not knowing about the fungas gnat I introduced these little buggers into my garden so now I am trying your product to rid myself of this problem I will follow up on my sucess.

  9. By diane on Jun 22, 2010

    For the last week or more we have had a very large number of gnats at our back sliding door every night. I have used yellow sticky paper, lemongrass, but nothing has worked. We can’t open the door or back window at night during this very warm weather.

    I have no idea what is causing this. We have never had a population of gnats in the backyard before.

    Can you please provide me with advice.

  10. By Justin on Jun 27, 2010

    I recently bought a few bags of organic soil from #@* #@%^ and found a number of fungus gnats in the soil when I opened the bags. I don’t want to simply waste the expensive potting soil so I spread it on a tarp in the sun to dry it out and hopefully rid the soil of the pests.

    Would it be beneficial for me to also use EcoSMART on the soil as it dries to ensure my pest problem is defeated before planting my rare vegetables?

    ~JustScience

9 Comments | The First 1,000 to Comment (Starting 12/21/2009) Will Become EcoSMART Product Testers! (details)