Ding dang soil gnats!

[comamma]

We end up with them every year in the house when we start seeds. Is there a way to kill them without killing my plants?

[Labradors2]

Next year, don't buy Miracle Grow!!!!!

I think I'm learning my lesson as every year I'm stuck buying MG and every year I get the little blighters here.

Remedies that I've heard are to let the soil dry out (hard to do with seedlings), put sand on the top half inch of the containers where the lavae hang out, bottom water, get those yellow stickies to catch the adult flies.

Good luck!
Linda

I have tried the sand on top and had the problem that water would not penetrate it. I guess it would work if you bottom watered, but I'm using deep 9oz clear plastic cups and the bottom would have to be soaked to reach the top. I also have homemade yellow sticky traps- they catch whiteflies but not fungus gnats, at least for me. (is the spellcheck here new?) or is it possibly in IE11 that I just got? Whatever, I really like it.

[Lorri D]

Because of where I live and our weather they blow or come right into the house through the doors as we enter and leave and our windows. I use soil blocks, so adding vermiculite, sand or Diatomacejous earth is not helpful. I had them extremely bad one year and had to do something, as they were killing all of my flower starts.

I tried letting the plants dry out to the point of wilt, peroxide, bleach, the vacuum, little bowls of fruity dishsoap, dish soap water drenches and yes the fly paper and nothing worked.

I finally bought some gnatrol and it worked. I know there has been discussion by some that say it is not safe on edibles, but my jar says it is safe on edibles and says it is for organic production. It saved my plants, but I would rather not use it if at all possible.

So, I plan on buying some Hypoaspis mites as I have heard good things about them, I just can never remember to order them on a Monday or Tuesday, hahahah. They are live so the company won't take orders for them after Tuesday to ensure they reach you by Friday. Hope that helps a little. Lorri D

[KarenO]

They are buggers and I got them in the house this winter from an amaryllis that was given to me. yellow stickies worked well for me. catch the adults= less or hopefully no eggs laid. harmless to all except the gnats too. I buy a brand called Safer's sticky sticks at Wallmart.
KO

[epsilon]

I've always been a visual communicator so here's what we used to do in Bio class. and this worked really well for us.

[Cole_Robbie]

I have seen perlite used as a barrier in place of sand.

[pipefitter508]

get mesquite dunks from lows put one in a 5 gallon bucket soak for 3 days an then use that to water
It will kill the larva an not harm your plants

[MissS]

This topic has been well discussed here
http://www.tomatoville.com/showthrea...t=fungus+gnats
Some very useful advise was given. I hope that it helps you.
Patti

[comamma]

I tried the mosquito dunk method two years ago and diatomaceous earth last year. If I can get some sand I will try that. I will also look up the sticky traps and Gnatrol, thank you everyone for replies.

[b54red]

I haven't had them much in my greenhouse since I began using UltraSorb to start most of my seeds. I sometimes get a few of them when I pot up early into potting soil and as soon as I see any I put about a half to one inch layer of UltraSorb on top of the soil. I have sprayed the whole greenhouse with Permethrin or Pyrethrin in a soapy water solution when they got bad in the past but I had to do it a couple of times to get rid of them. I sprayed everything inside the greenhouse and not just the potted plants; but that would not be a good idea inside the house.

Bill

[clkeiper]

Try to let the potting mix (no matter what you use) dry more between watering. I have drenched mine with 3% peroxide, too. Seems to help because it works on controlling the fungus in the soil. Maybe water from the bottom if possible, use a fan to keep the air moving around the plants, too.

[epsilon]

Carolyn K

I actually used to think the same thing and I had used it liberally to control it when I was growing orchids, but it turns out according to Mycologist Paul Stammets. Hydrogen peroxide may only be mrginally effective in stopping fungus growth but actually in the end will help it thrive. Fungus produces h2o2 as the mechanism by which it breaks down (oxidizes) and absorbs nutrients, also fungus are oxygen breathers so unlike the aerobic bacteria that thrive in low oxygen high moisture environments the fungus will thrive and soon overtake the medium because of the absence of competing bacteria. H2O2 is an awesome control for bacterial rots no doubt but you'll eventually find more fungus as it will bounce back twice as fast in the "microbial vacuum"

[roneraines]

Has anybody tried cinnamon. It is supposed to be an antifungal it may help.