Fungus Gnats!

[kevinhannan]

I know exactly what gets rid of them, but you can't use this solution (pun intended)
on seedlings or young plants. This recipe comes off the branded product...

1 litre of (de-chlorinated tap) water
1 tsp of washing up liquid
3 tsp of cooking oil

put it into a sprayer bottle and shake like mad, then spray away during cool part of the day.

Continually spray away as you use it, as the contents will separate.

The idea is the water is the carrier, the washing-up liquid is the carrier also and surfactant to make it 'stick'
and the oil coats the bugs to sufficate them.

Depending on the bugs, there will be eggs, so re-apply as appropriate. Sometimes, maybe 3 or 4 applications
are needed to get rid of them.

Young plants cannot cope with this and usually die, becuase the plants have fewer 'breathing holes'.

 

[woodmort]

Quote:
The "Knock Out Gnats" that I recommended is a nonpoisonous bacteria that won't harm anything but the fungus gnats. Not only that but the bacteria live in the potting soil so prevent reinfection, unlike sprays that will eventually become ineffective and can be indiscriminate. The stuff Gardens Alive sells is all environmentally safe. I highly recommend them if you're into that kind of thing.