21 day update.
In my never ending quest for truth, justice and a pest-free, indoor, organic garden, it’s my sad fate to announce fungus gnats have returned, and this time, with attitude.
Within a 48hr period my virgin yellow stickemup traps had been violated no less than 40 X by those lil’ buggers!
Over the years that I’ve battled fg’s, I’ve probably tried every method on the web for stopping these brutes, …twice.
Time for a review:
Insecticdal soap/ (potassium salts) spray only = initially effective, short duration(have to reapply)
Neem / spray only = 98% effective, takes down population quick though incompletely, short duration(have to reapply) drenching can harm a plant.
Pyrethrins / spray and drench = Effective but as a drench,damages soil’s microherds somehow.
Dawn regular or Joy(lemon) brand dishsoap / spray, drench and soak = 100% effective, kills insects at all stages by suffocation, not chemically or by nerve agent.
PITA, long soak times for soak, multiple rinses, though easier to re establish micro herds. 100% necessary to bring in plants from outdoors or other growers.
Mosquito bits(Bacillus thuringiensis ) / drench and soak = 98% effective though some live through, have to reapply regularly.
Organic mulches, rice bran, pine bark / n/a = tend to increase and attract fg’s. Mychorrhiza fungal treatments do as well.
Raw Charcoal Powder mulch / n/a = Tested, but not completely, some limited success. At the time of this testing, my second attempt using RCP failed due to lack of sufficient supply. Needs retesting.
Observation suggests RCP as a dead, inert material provides quite a barrier to fg’s. Would have to bottom water after application, good for SIP’s. 1/2+ deep.
Sharp sand and “Play” / n/a sand = Sharp sand has bigger particle size than play sand, less chance of caking.
Despite its name, sharp sand particles are rounded, not sharp, fg’s can navigate very narrow gaps like sharp sand has.
My current test, crushed granite/grani-grit starter (EDIT) wrong size, see my next reply below.
And Pot-Popper nematodes applied before granite mulch.
Grani-grit starter is maybe double the particle size of sharp sand but is shaped like chips or mini slabs, no rounded edges. Doesn’t cake with watering, though I think some additives like molasses would.
Here are nematodes, my first grow, second application to these pots.
Each pack for 5 gal of soil, my grow has approx 2.3 gals of soil. I’ll use a whole pack.
All done.
This am NO fg’s had violated the other virgin side of that stickemup trap.
Those leaf tips sneaking in there is my only surviving Afghani Gold that I had at another location. Lopsided branching. She hung on like a champ when all about her were dropping off.
I just upped the cal/mag by a third, from 4 drops per 50 oz to 6 drops.
Forgot to mention I installed 120watt FS led blurple, expecting that bleaching to go away.