When Don K was in Floriduh, he was kind enough to share some smuggled seeds wif me.  I put them in community pots in my garage to keep the squirrels and rats out of them. They are germinating now but have those little gnats flying around them.  The soil in the pots is regular potting soil below with an inch or two of zeolite (a volcanic mineral similar in looks to perlite but heavier) on top.  I have never really set up for seeds so although I have been growing palms for decades, I rarely went the seed route.  What do I do?

Tanx,

Jerry

We used to use chemical to prevent/eliminate them. Now we use a biodegradeable hand soap. We apply the gel/liquid soap at the top of the medium in the containers then water them in. A few flushes over the next few days will cause foaming and suffocates the gnats without the use of chemicals. Concntrated soap works best. Palmolive has also worked for us and works well as a wetting agent, too. I would suggest the bio hand soap on seeds.

I would also suggest using a sterile media for germination - peat moss instead of soil. Fungus gnats tend to appear more frequenly in overwatered plants/seeds, too. A fungus treatment would be a good idea too. Where the gnats are, fungus will eventually appear.  

Good luck!

A few more items that worked for me are Yellow Fly Paper near the pot.  The gnats are attracted to the color yellow.   Ever notice how commercial greenhouses have yellow sticky paper all around the perimeter??

Check out GNATROL too:

http://www.gtghydroponics.com/store/0-0-476.htm

This is what I used and it worked great!

Good luck. Jeff

They are a pain and I reckon garlic fends them off.

Whilst initially they tend to feed on decaying matter sooner or later the larvae turn to the tender roots and cause damage, and the flies will soon spread any fungus around all your plants.

I agree with John that the basic condition is that the pot medium is kept too moist.  The fungus gnats only appear with too wet media.  It's tempting to overwater precious seeds or plants but a slightly drier medium will preclude the gnats. (trust me!)  When I have had the gnats I use the yellow sticky traps.  They really work.  Here in California I use traps from  www.seabrightlabs.com.