ButterflyLady29
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Fungus Gnats finally under control

For years I have battled fungus gnats, losing in most years. They've devoured sprouting seeds, nibbled the inside of Christmas cactus roots, flown up my nose when I'm napping, and generally made growing plants indoors a difficult practice. Oh I've tried to get rid of them. Used all kinds of insecticide, tried drying out pots (not easy when you're starting seeds), used sand in the potting mix, etc, etc. Finally I found the best and easiest solution. STICKY TRAPS!!!! They don't work on the soil dwelling larva but once the adults are out and flying they sure do love to land on whitefly sticky traps. I couldn't believe how many gnats I had around until I saw them on that bright yellow sticky trap.

I bought more traps today. The last ones were pretty icky. It may not be 100% effective and you can't prevent a reinfestation from contaminated potting soil (which is where I think the original infestation came from) but it sure helps enough to be worth the cost.

I had used flypaper strips before but the new ones dry out and turn hard after only a couple days under florescent lights. The sticky traps don't dry out.

pepperhead212
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I tried the yellow sticky traps for fungus gnats years ago, but since they kept showing up in large numbers, as well as appearing around the house, it didn't seem I had them under control. This only happened when I tried Gnatrol, which, back then was a liquid concentrate of BT israelensis, which I bought in 1 qt. containers, which lasted two years. They later switched to granules, at outrageous prices, with the liquid only available in 2.5 gal or larger containers, so I found something that did the same thing, and is even more concentrated - Microbe Lift mosquito control for ponds. !/2 tsp/1,000 gal in a pond every two weeks, to give you and idea of concentration! I figured out that only 8 drops would do the same as the 2 tsp. of the old Gnatrol liquid. I use it by moistening all of my soil starting mix, as well as in my large pots, that I bring indoors for the cold weather, and never see any fungus gnats! I add a very small amount to about every third watering to the pots. This 6 oz container lasts me two years; I refrigerate it most of the time, though the label says that it can be kept for two years at room temp, once opened. This is the best source I have found for it, but then, I can always order enough for my fish tanks, to get the free shipping.
https://www.drsfostersmith.com/product/p ... atid=12263

As for the yellow sticky sticky traps, I got a 200' x 4" roll of the stuff! I use it mainly for pepper maggots - not for control of them, but to see when they are gone. In the early season, and again in mid-July I stick some on the agribon that I cover my peppers with, to stop the pepper maggots, and a BUNCH get on the early traps, then some some show up on the later one, but when it seems I stop seeing more, I put some fresh strips out there, in late July or early Aug., and when there are no more being trapped, the covers come off! It traps a lot of other insects, as well, so I don't like to use it all over, as good insects are also trapped. But it works great for this. However, do not get this stuff on you, or anything else - it is not easy to get off, even with things like acetone! it really is sticky.

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applestar
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Oooh sounds good pepperhead212. Maybe I will be able to order some pond supplies along with this. :D

pepperhead212
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And on a related topic, apple, in the reservoirs of those SIPs, to prevent breeding mosquitos, I break off pieces of those mosquito dunks (same BT as the active ingredient) and drop them in every couple weeks. This also prevents the fungus gnats, which can be a problem in outdoor pots, even though we don't think about them outside.

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applestar
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ButterflyLady29
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I tried the mosquito dunks in the potting soil and in the water when I watered the plants. They did work when the pots were dry and able to be really soaked. Didn't seem to work so well when the pots were already damp. I used some liquid nematodes years and years ago and succeeded only in drowning several plants. I guess it's one of those things where what works for one person may not work for another. I'll be the first to admit the gnats aren't 100% gone but the numbers are down enough that I am no longer losing seedlings or plants to them.

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rainbowgardener
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@ButterflyLady - Many house plants tolerate allowing their soil to dry out better than you would think. I usually only water house plants twice a month (but I mist the leaves daily). Drying the soil out between waterings takes care of the fungus gnats, which have to have moisture. If you can't let them dry out, have you tried putting cinnamon in the water? I keep a watering can full of water, to let the chlorine outgas from it. Just add a pinch of cinnamon powder to that water and stir before you use it. It is a natural anti-fungal. It kills the fungus in the soil that the adult gnats live on. Since it doesn't kill the gnats directly, you won't see an over night difference, and even once you have starved the adults out, more eggs will hatch and more larvae turn into adults for awhile. But done consistently, it will keep the fungus gnat population very low.

ButterflyLady29
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No, never tried cinnamon in the water. I never heard of that one.

Watering is really variable here. Some plants can get by with less frequent watering because they are further from the heaters. The ones near the wood burner dry out really fast and can't get by without more frequent watering. I don't have the problem so much when the heat isn't on in the house but when the heat is on those poor plants dry out pretty quickly.

pepperhead212
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rainbowgardener,

The only problem with the cinnamon is that it will also kill the beneficial fungi, like micorrhyzae.



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