herbal bug repellent for plants

Can anyone tell me of a homemade recipe I can make to keep the bugs off my plants. I have already tried the soapy water spray ... worked, but not well enough. Can the oils of one herb be taken, diluted, and then sprayed on another herb without effecting it's taste or benefits?
Thanks, Jolene

I have used the "Garrett Juice" for 2 years now and it works. However, you have to reapply often. Here is a link to his recipe. Explore his site...it is very informative.
http://www.dirtdoctor.com/recipes.asp

Great site, Lantana. Thanks.