I tried the sand method and it didn't work for me. Also tried the cut potato
method (lay a cut potato on the soil, the larva go to the potato), and that
didn't work, either.
________________________________
From: "gardenpt@aol.com" <gardenpt@aol.com>
To: pbs@lists.ibiblio.org
Sent: Fri, March 25, 2011 11:16:07 AM
Subject: Re: [pbs] Fungus gnats
I read that pouring a layer of sand on
top of the soil in a pot would eliminate fungus gnats,
reportedly because the sand cut up gnats or their larva,
Nice thought, and widely believed to be true. But not so.
Instead, use Bacillus thuringiensis israelensis (Bti) as was suggested very
early on in this thread. Use the Bti (dissolved in your irrigation water) for
at least 3 weeks to break the gnat's life cycle.
Jean in Portland, OR