I haven't had bugs since I started growing about three years ago. Someone decided I needed to learn, and I discovered I have the start of a fungus gnat infestation today. It's a great day for it, as no one here in the Halifax area has remedies in stock. I ordered nematodes and yellow sticky traps through Amazon, but they won't be here for a week. To keep the gnats down to a dull roar I deployed some cut up fly paper strips around the plants.
Ah, those pesky feckin gnat bastards. I just love those. [/sarcasm]
However, I do have some tips that will help.
First, the ones flying around. The yellow sticky strips will get a few, so keep that up. Also add some coffee cups filled 1/4-1/3 of the way with apple cider vinegar around your grow.
Now to eradicate these pesky jokers, it's good to understand how they cycle (and they cycle very quick) and how to break that cycle.
They love moist and dark areas. Drains, that potato at the bottom of a sack starting to soften and go bad, etc. I had a horrid, horrid infestation with my house plants that I bring inside in the winter a few years ago. I mean it was bad. Those things were everywhere in the house. Every window sill would be covered with their expired bodies, and I can't tell you how many times I had to windex the TV from the smears of their demise.
I dug and dug into it all, and finally found what worked in the long run. Needless to say, I haven't had an issue since. Not once.
The strips and ACV will get the fliers, but really unless you break their breeding cycle you will not be rid of them. You can spray (I tried them all) but they will come back. Why? Their eggs. That's the kicker, and they lay them thick and often.
I found that they absolutely loved the top of my potted plants. Nice and moist, and the perfect spot for their reproductive escapades. They were having a party like it was the 60's and free love. It was bad. Bad bad bad.
What I ended up doing to break that party up was put about 1/2" (12mm or so) of sand on top of my plants. Just that regular old "play" sand (that's fairly fine) from the home improvement store. It sounds odd at first, but it works. They absolutely hate the sand, and will not go near it one bit. I guess it's like glass and cuts the crap out of them, so they avoid it like the plague.
Early on, I also had to keep the drains closed in all the sinks and tubs to take away another dark, damp area. Within a week, they were all gone. I've always had sand on top of my plants since, and never had another one of those buggers.
I also started watering them from the bottom, but that's only because it isn't as easy to get them gently watered from the top.
There are some additional benefits as well. One is it acts like a mulch, and reduces evaporation from the top of the soil. So it allows more water to go to the plant, and in turn each watering lasts a little longer as well.
Anyway, it's a solution that works. Sometimes you have to adjust to make it work, but that's better than those feckin gnats.
