I just mixed up a while back about 50 gallons plus of organic soil from bags. I was about out of my previous mixes and its the same suppliers as I have used with great success in the past. However I may have gotten a bag or more that had possibly some fungus gnats from somewhere. Anyway I used the same mix for 4 five gallon bags in my tent, and replacing some bonsai moms and starting clones etc. I have not seen a single gnat for at least a couple years after learning not to over water a long time back and rarely if ever saw a single gnat. Ancient history, fast forward to last couple weeks and I have had more than a few gnats in my grow and moms etc. They are separated somewhat some I am pretty sure the gnats were in a bag of the compost or soil or ?? Not going to sour me on a proven past good soil products.
Anyway Im beating them back and almost gone with Gnatrol and yellow strips. My question is can I buy nematodes and mix them in the top foot of the two 30 gallon rubbermaid trash cans I currently store mixed soil in ? Will they all die once the cans dry out as they usually do ? One can is outside with holes drilled in lid and bottom when I used to put worms in my mix and the other is stored in indoors and dries out over a couple months totally. The can outside stays somewhat damp all year but the one inside dries out totally and I usually mix water in the bags for a day when I use it to hydrate the soil before planting into them. Have not had this issue in the past of my soil seemingly coming into the grow area preloaded with gnats maybe.
Short question is do Nemotodes go into stasis when there is a lack of moisture so long as its not below 60 or so?
From what I have read they will die off as the food disappears, they don’t have a long life cycle either, if there is food they will keep breeding.
I used predator mites to kill off my fungus gnat infestation I had after using a different compost mix, it was so bad there would be a hundred gnats on a 6x8 sticker before I even got it tied to a light lol.
They cleaned out the gnats in about 3 weeks, I hardly ever see one now, the Predator mites are still active I see them in my soil now and again when up potting my plants.
I think they would be a better option for you in your outside bin, so long as there is food they will stay around and breed.
These are the ones I used.
Thanks for the advice. I was looking at the very same critters from a place called Natures Good guys and maybe some nematodes as well. I am still not sure if the indoor stored soil will have all the gnat eggs, if they are in there, die off over a few months since like I said the soil drys out 100% in the can in a dry utility room with the central air/furnace, hot water heater etc in the garage. It never gets below 60ish in the winter or summer. I still have a 8 plus 2 CF bags of the soils and compost which should last me a while. Last night I watered with more Gnatrol all bags in grow tent and all moms in separate box. Saw one gnat in each location but sticky traps are clean. I think Im about past this but will treat every 3 days for another week plus and then try to do preventive once a month maybe.
I’ve used both the nematodes and the grub grenade predator mites.
The mites are better IMO, and definitely last longer in the soil as long as theres a food source.
The predator mites like a drier environment than thrips and fungus gnats do.
Thanks for all input. Going to get some predators and do my grow and moms and sprinkle some on the mixed soil in storage. Have to follow directions and moisten the soil as per directions. For the moment the gnatrol has wiped them out it seems but the predators will go a long way to prevent this again and I am going to get more to use on all my outdoor container veggies etc.
I’d pasteurize what’s in storage if I had time.
Im going to revisit this just for passing on stuff. I resolved this with buying a supply of these. https://www.naturesgoodguys.com/collections/fungus-gnat-control/products/hypoaspis-miles-predatory-mites-12-500-insects?variant=23358282627
They along with Gnatrol and yellow cards got this under control but the Good Guys predatory mites are what did the deed. I just started some cuts in small pots to uproot to bags in a few weeks. Anyway I found two random flyers on a yellow card so I went back to my bonsai moms. I put them under my USB microscope and found in each of the 6 moms I still had the mites crawling around doing their good work. After locating small clusters of them on the moms I scooped them up and put them on the new plants to spread the love. The Hypoaspis miles - Stratiolaelaps scimitus - Predatory Mites I got from natures good guys were doing fine without gnats to eat just tooling around consuming bits of leaf trim etc on the top of the small pots. Im going to see if I can harvest some more from my 5 gal grow bags in a couple weeks when I harvest to put on new pots and moms. Now that I have the coloney spread out on 3 different small groups of pots Im curious if I can keep them going and not have to buy more. They definitely worked in finally ending the gnat scourge. Im 100% sure this whole problem came in on a supply of bagged soil which is really good stuff from past experience but something happened to contaminate at least one bag.
Buy once and then make your own nematode bombs , just keep the cycle going , great fun
Use cheap weed control fabric to create a barrier on inside of holes in bottom of pots etc , gnats hate that , no access : )
And bottom feed so medium dry on top , plants love that and also Bye bye gnats win win : )
Do the mites survive and work well in coco medium?
I have a good infestation of gnats and I am undecided about nematodes or mites. Here I can obtain them at almost the same price… but want to make a good choice.
Are you in reg plastic pots or fabric pots or airpots
Cover top of pot in weed control fabric and cover any holes in base of pot in weed control fabric
Gnats will be gone
Bottom feed for the win : ) gnats usually appear from overwatering
Bottom feeding keeps surface of soil dry and weed control fabric keeps them from entering holes in bottom of pot
: )
A very dense medium may hinder them, I would find them in my soil up to an inch down, but I use a lose organic no till mix with lots of room for them to move through the soil.
I find they will still lay eggs on the bottom edge of a cloth pot that stays moist, but bottom watering is definitely a lot better.
I’m in 5 gal grow bags and using the hypoaspis miles are still my go to. I purchase resupplies of the mites occasionally to maintain them and check all bags and bonsai moms.
I recently discovered a lot of them in my freshly mixed soil in a 40 gallon can in my utility room. A LOT. They overwhelmed the yellow sticky I put in the can before the order of predators were delivered. And I sat this in the utility room which is usually lights out.
And the stickies looked like I spilled a black pepper shaker on it. Got predators and added some nematodes this time and applied them to the 30ish gallons of soil and within a couple weeks there is very little signs of the little bastards.