• 3440
    • Knock-Out Gnats™ Granules - 4 oz (makes 15-125 gallons)
    • $29.95

Knock-Out Gnats™ Granules

Stops fungus gnats with concentrated easy-to-use formula


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Product Details

This strain of Bacillus thuringiensis (Bt/H-14) provides very effective fungus gnat control for houseplant growers and home greenhouses. Populations of fungus gnats (often called "fruit flies") usually peak during winter and spring. The tiny adult insects lay their eggs in peat moss, humus-rich organic soil and potting media. The larvae then feed on plant roots, including those of young seedlings.

With Knock-Out Gnats, the larvae ingest the larvicide and die! The water-dispersible granules are convenient to use!

Light infestation - 1/4 to 1/2 tsp per gallon
Heavy infestation: 1 to 1 1/2 tsp per gallon.
4 oz. is approximately 48 tsp. Using the 1/2 tsp rate, it will make 96 gallons. Using the 1 tsp rate will make 48 gallons.

Customer Reviews

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no more gnats!

Jan 23, 2016  |  By Megan Lim
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My worm compost bin was infested with fungus gnats and I couldn't get rid of them! I spent months trying to kill hem but it wasn't enough. 3 applications of knock out gnats and the gnats were gone for good without harming the worms!

Love this product

Jun 23, 2013  |  By mark
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I work in a sealed office building (cannot open the windows). Over the years people brought in gnats with their plants. Since the office is sealed, natural predators cannot get at the gnats. I found this product here when desperate for something to knock down the gnats. I had been warned I would have to remove my plants otherwise. It worked quickly. Periodically I would refresh it with a simple watering of this product. I used it on the plants of some coworkers when they let me. I ask management to authorize me to use it on the other plants in the office. Still waiting for that. But at least management knows this product exists. Without question it kills the baby gnats breeding in the soil of the plants. Here back for more of it.

knock out gnats

Feb 26, 2013  |  By Rebecca
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This product is very useful to me, please continue to allow it to ship out to the state of California. I have a severe problem with gnats and the larva need to be controlled. I still have some of it and I noticed a major decrease in the gnats after I used this product within two days. I want to order more in the future to send here to California. Thank you.

    • 3440
    • Knock-Out Gnats™ Granules - 4 oz (makes 15-125 gallons)
    • $29.95