fungus gnats

At this point I am on the verge of callin' it an unmitigated disaster. Game over, you know? I am lookin' for small victories now and any one of them would sure feel like a major breakthrough. 

Worse than the temperature and wind chills this winter (if you can believe anything was worse) and a source of even more devastation was the fungus gnat.
I had researched and read and googled my brains out and finally got a couple of grow lights I thought were sufficient for my needs. It was October maybe or November and I wanted to see green things growin'. With a rudimentary set-up I embarked on a flight to destiny. I was gonna have my own nursery and it all began with there, under the sink in my bathroom. Then the other bathroom. January and the Japanese maple seeds had been stratified long enough. And I brought dormant hydrangeas and a Japanese maple in. All of which I had rooted by takin' cuttings the very first summer I learned about the miracle and magic of propagation.
I wanted an advantage. I wanted to have my hydrangeas bloomin' before the local big box stores. In my fervor I and inexperience I over watered all the plants we spent the winter steppin' around. Enter the fungus gnat. Resemblin' a mosquito, he deposits the next generation in the wet soil so that generation has some organic material to feed on. The wormlike larvae mutilate the roots of standin' plants. Needless to say I lost everything, even some mature healthy plants.
Neem oil is the preferred treatment for fungus gnats. Problem is I live in the mountains of eastern Kentucky. There is no neem oil here. I remember when my hometown got its second traffic light. Before that, someone would shoot the first one out every weekend, or every time it was replaced.
Winter stretched on and the formidable fungus gnat multiplied exponentially. In my innocence I assumed once I took the plants outside the problem would just take care of itself. Now I know how naive that was. I built my hoop house, unheated polytunnel, and moved the plants and effectively ended my season with that action.

I read about the rose breeders usin' a layer of perlite on their pottin' mix to thwart dampin' off. When I ran out of perlite I used sand from my daughter's sandbox, hence the pink topdressin'. But, it works on the dreaded fungus gnat. A lot of times they will escape in winged, adult form out the bottom of the pots. They can not penetrate the sand to re-enter their snug, preferred environment. As far as the damagin' larvae, I don't know. I have tried peroxide, vinegar, all the organic cures found on the internet. The best thing to do, in my opinion, is let the soil dry as much as you can and just weather the storm.