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Eco friendly fungus gnat killer

Hi I am wondering if anyone has heard of Beneficial Nematodes? They are tiny little micro organisms that eat fungus gnat larvae! I just watched a greenhouse video on YouTube about them they look awesome!!! I tried H2O2 because that seemed Eco safe but the larvae don't die on contact. (I put some in a glass and added H202 mixed with water and nothing happened). Anyway I want to order the BN but I don't see anyone else mentioning them. Maybe this is a newer gardening tool? Looks easy just water your plants indoor or outdoor with BN mixed into water. I'm curious if anyone else has tried this?

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Green Thumb
Posts: 383
Joined: Sun Apr 01, 2012 4:22 pm
Location: Western Massachusetts Zone 6a

Windsoryardner posted about the use of beneficial nematodes in their community garden in this topic: ... +nematodes

I hope the link works :? but you can also do the search by entering the words beneficial nematodes and the topic is somewhat near the bottom of the search as it is on a post that started in 2011.

I didn't see anything on using them indoors in the posts however.

Hopefully this helps. :)

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Location: Hawaii, zone 12a 587 ft elev.

I heard of them, but the State of Hawaii quarantine laws will not allow them to be imported.

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Super Green Thumb
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Location: TN/GA 7b

I have heard of beneficial nematodes haven't used them.

Fungus gnats need moisture, so you can usually control them just by letting your plants dry out pretty much between waterings. A little cinnamon added to the water helps too - it is a natural antifungal, that helps control the fungus the gnats live on.

MI Gardner
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Joined: Sun Apr 27, 2014 2:26 pm
Location: Michigan Zone 5 (Mid-MIchigan)

I was plagued with these gnats. Here is what is working for me for the second year:

A biological solution

1. Bonide 803 Thuricide BT (Bacillus Thuringiensis) Insect Killer - This thick liquid mixes with water to apply to plants. Within 72 hours the gnats are gone. Reapply in a cycle to prevent them coming back.

2. Bonide Mosquito Beater Water Soluble Pouches. If using a seed propagation system with expanding fiber disks and water in trays with a water conducting mat. Drop one of these granule packets (the packet will dissolve) into the water tray. I did not have any gnats this year.

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