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I started out with a few house plants a couple years ago. In the last year I have alot of out door potted and grounded plants.. So I am still relatively new at this..
During the summer GNATS have taken over my house... I have tried many things that I have read just on the net as to what to do... Even tried Thuricide Concentrate mixed as per the label. I have treated 3 times, drenching the plants.. It appears to calm down for a short time but then I'm attacked by those pesky creatures again. I really do not know what else to do. Quite a few of my "houseplants" have become patio plants and are thriving, but surely still with the gnats. Ugh!!
I have a thought.. but please someone stop me if I am about to become a house plant murderer, as this is very pre-meditated. I am wondering, as it is early fall here in Alabama..if I repot all of my houseplants. New medium is where I want to start. I have read that if I cook the soil in the oven to specs that it will decontaminate the soil. When repotting I normally take some of the native medium with the plant into the new pot.. However this will bring along the culprits and their larvae..
Is it safe to clean all the old soil from the roots and repot completely using new, decontaminated soil? Am I going to kill all my house plants by doing this??
Please someone help me.. I don't want to kill them all but I am truly at my wits end. Not being able to sit down to watch TV with a glass of iced tea without finding a gnat in it two seconds later is killing me.. DRIVING ME CRAZY.. not to mention the darn things flying up your nose is quite annoying..
Good morning Daisy; "dual action rose and flower insect killer" by Bayer. Is a very effective product. Try before you get "drastic" Good luck. :) Daisey
yes baking the soil works to sterilize it. I have waaaaay too many houseplants to even consider doing that...anyway yes you can wash all the old soil completely from the roots it only hurts if you don't repot them right away
I know Bacillus thuringiensis israelensis (the kind of BT used on mosquito larva) works for fungus gnat larva. I don't remember all the details right now, but you can google for more information.
Ok, In looking into this more I realized that the Thuricide I have been using is a form of Bacillus thuringiensis israelensis.. As it has not been working for me (maybe my infestation was too large or overwhelming for it) I went drastic. So all weekend, I have cooked soil and repotted plants. Seems to have worked so far..xx fingers crossed xx. I am still killing the adults that are already flying but there seem to be less, by a long shot. I was able to have a few glasses of something to drink without finding bugs in it..
I sure hope that it last.. this has been alot of work. It seems that my plants have survived the drastic measures. I repotted, and watered them, made sure they were drained extremely well. The only one that is drooping is my beautiful Scheffalera. I think it will come around. I bought it almost dead from Lowes... (they don't take good care of their plants) and I was able to revive it and it has been thriving. Surely it will come back from this.. Droopy but seems to be perking up.. Again my fingers are crossed!
Scheffalera is a hearty plant. My wife has four of the biggest ones you've ever seen. Wait until it dries out pretty good between waterings, then give it a good soaking.
Actually Thuricide is a different subspecies, Bacillus thuringensis kurstaki, and is for killing caterpillars. It will have no effect on gnat larva at all. You have to have the Bacillus thuringensis israelensis to kill those nasty gnat larva. It's confusing. The israelensis is most commonly found in mosquito dunks. You can crumble them into a jug of water, let them soak a day or two, and then water your plants with the innoculated water. The bacteria will then be in your soil and will eat up any larva that hatch in the soil. If it were me, even with the now clean soil, I would water with the BT innoculated water for a few weeks just to prevent the cycle from starting over again. In fact, I need to do it to some of my plants because the gnats are becoming a problem. Aggravating creatures! Good Luck! :)
Jim41, Thanks for the info.. It just made me smile. I don't want to lose that plant. I really like it and since I'm still kinda new at this, I am really proud that I saved it from near death.
Danita,
Thank you as well. Good info and I fully intend to follow your advice.
I ended up repotting ALL my plants with new medium that I baked to specs, then allowed to cool completely. Its been about 3 weeks of NO GNATS... Love it.
I will start the mosquito dunks probably this weekend and use them periodically just to protect against re-infestation.
