Went organic last year, but results were hit and miss. I didn't use any sort of weed/feed in the spring, and other than some dandelions that emerged temporarily..it wasn't bad. I've never done any pesticides. Corn Gluten didn't seem to do jack shit with the crab grass.
I am going back to regular pre-emergent this year, and will try and stick to mainly non-synthetic afterwards. Soil temp is still 46° so a ways to go before it can be applied.