Question
I have started my garden for this summer and have two indoor green houses with several dozens seedlings growing in each green house.  Each green house seems to be infected with black gnats.  I have tried spraying with liquid detergent and this does not work.  The gnats are all over my house what do I do?  

Answer
Diane, it sounds like you will need to resort to a more harsh insecticide. Since I am a firm believer in organic controls, I always recommend rotenone or pyrethrum when insecticidal soap proves ineffective. Both of these products are organic, meaning they're non-toxic to humans, pets, and the environment. They are made from plant derivatives, and break down in the soil with no residual effects. They are extremely effective against most of the insects which infest the garden.

Attached are links to two companies that market both products.

http://www.gardensalive.com/product.asp?pn=8659

http://www.gardensalive.com/product.asp?pn=8101

http://www.planetnatural.com/site/pyrethrum-powder.html

I hope this answered your question. Good luck, and please write again if I can ever be of assistance.      

Regards,

Mike