gogogadget Posted May 27, 2011 (edited) Dear Garden Guru, I have been getting gnats in many inside plants. I had them this winter and I changed soil and cleaned plants time and again and thought I finally was Ok, but they keep returning, never a problem till this winter. Please help me thanks. A: The soil or fungus gnats become a problem when the soil is kept too moist and not allowed to dry out much between waterings. The larvae of the gnats feed on the small fungi that are decomposing the organic portion of the potting soil, primarily peat moss and mushroom compost. Too many larvae in a pot and they can begin to feed on the plant roots as well. To control them, keep your plants on the dry side. You have already gone through the changing of the soil. Sloat carries beneficial nematodes (aptly named fungus gnat destroyers) that can be applied to the problematic containers. The nematodes eat the larvae thus breaking the cycle. Small yellow sticky traps called Gnat Stix can be attached to the rims of the pots to catch the annoying adults. thought id share with you all Edited May 27, 2011 by gogogadget Share this post Link to post Share on other sites
obtuse Posted May 27, 2011 They are bastards indeed. bastids. Cheers, Obtuse. Share this post Link to post Share on other sites
applesnail Posted May 27, 2011 (edited) yeah ive found nematodes like Steinernema feltiae and bacteria like Bacillus thuringiensis to be to slow and not always successful, ive found nuking the soil with a hydrogen peroxide (i use 0xy plus by growth technology http://www.growthtechnology.com.au/ssl60/0/ oxy-plus kills em much quicker and takes away all soil nastys and diatomaceous earth mixed thru the earth works to keep them away as it drys there larvae, although after an oxy treatment one has to add a garden compost or beneficial microbes back into the soil enviroment again and for this i recommend vitalink bioplus http://www.vitalink.eu/en/_range/_additives/vitalink_bioplus.htm These little buggers also build up a resistence to pyretheum and any other insecticides, i swear they are worse then cockroaches and politicians & one day rule the world just like pinky & the brain, every mouse wants to rule the world! Edited May 27, 2011 by applesnail Share this post Link to post Share on other sites
gogogadget Posted May 27, 2011 (edited) laughs, yea i've used oxy plus in the past i think i may have some laying around i was trying to go organic as i've spent the best part of the last few months getting soil conditions right, but they dont pose a huge problem with bigger plants but are playing silly buggers with my seeds, fly spray knocks out the flys but only want to use as a temporary solution, Adding about 1 inch of sand to the surface area of the mix can trap the flying gnats below the sand and prevent them from escaping to mate and lay egg, A thick layer of perlite can have a similar impact but like the sand better because it is heavier and stays put longer. Either of these will promote drying at the surface which the larvae can't tolerate. Using an old table fork or similar tool to vigorously till the top layer of soil is another tip as this will promote drying and crush larvae and eggs that are present. ps, least its probably over watering bringing them, easy fixed thankyou all for your help. pps, and a HUGE thankyou to oxidizer for helping me diagnose my parasite. Edited May 27, 2011 by gogogadget Share this post Link to post Share on other sites
applesnail Posted May 27, 2011 yeah me to gogo im in a cold enviroment, these flys drive me nuts, ive tried everything and the best natural thing ive found is DE but the adults walk thru it now worrys, and its meant to be like razors for insects, but i have found it does kill the larvae and dont seem to breed as much in a DE mix, and the gnat traps stick em everywhere the more the merrier..i tried so many natural things and in the end i went nuclear with the oxy which is good for the roots system anyway..... i lost a lot of loph seeds this year to scarids and since i started with the oxy they have vanished another good one that kills em is dutchmaster zone, this can be used in all soil enviroments also... im yet to try this product which is made from neem and sounds promising http://www.generalhydroponics.com/genhydro_US/azamax.html you can buy it in oz but will have to shop around! Share this post Link to post Share on other sites
gogogadget Posted May 27, 2011 this could well be a great all rounder, AzaMax™ Botanical Insecticide, Miticide, and Nematicide thanks once again i've been researching nematode parasites good and bad Share this post Link to post Share on other sites
AndyAmine. Posted May 27, 2011 make sure you use horticultural grade DE, pool filter DE is crap. Share this post Link to post Share on other sites
Torsten Posted May 28, 2011 we've used pool filter DE and it worked fine on gnats. removing adults via traps is by far the best defense though. you can also try applying yates 'success' which is an organic contact and systemic insecticide. Share this post Link to post Share on other sites
WoodDragon Posted May 29, 2011 Yellow sticky traps do work well. So do potties... my daughter carted hers into the lounge room where I have some seed trays on a window sill, and without me knowing she made a number 1 deposit and wandered off. Two minutes later and there where several gnats in the bottom! Share this post Link to post Share on other sites
AndyAmine. Posted May 29, 2011 I found the pool fliter grade about 1/3 as effective in my personal experince, Share this post Link to post Share on other sites
applesnail Posted May 30, 2011 yeah the azamax is expensive around $120 for a litre but its very concentrated , and your better off buying bulk like a litre, bunnings sells eco neem which is the same product but it only comes in 100ml bottles and will cost you as much as a litre probably,PM me if you want details where to get it near you, i got head office distributor number here that can put you in touch with a local source for azamax, i had alot of trouble finding this product, without some serious googling...LOL Cheers! Share this post Link to post Share on other sites
Gunter Posted May 31, 2011 clarified extract of neem oil is also an effective organic way of controlling both these as well as scale and root mealie bugs. Share this post Link to post Share on other sites
applesnail Posted June 13, 2011 (edited) i forked out the cash for the azamax and in 2 weeks of treatment my hothouse is pretty much pest free, im sure there are some little critters lurking somewhere but to this eagle eye it is looking much better, gnat numbers are miniscule & i had severe problems with flea beetles as these little buggers reside in large numbers in my garden beds surrounding the house under the woodchip mulch my landlord decided to use and have decided to venture & dwell in my pots, which i didnt know they were calling home until i repotted some acacias, and when i dug em out of there pots it was flea beetle & ant metropolis in there which was unknowing to the eagle eye, so i soil drenched with azamax @ 7day intervals and NEEM KICKS ASS.....Azadirachtin a blessing from the neem kernal, this by far of the most effective insecticide i have come across well worth the money @ 2-3ml per litre one can definately see there cash well spent in this product...well this chimp can! Edited June 13, 2011 by applesnail Share this post Link to post Share on other sites