If you want to grow organically, it all starts with the soil. Much of the soil in people's yards has chemicals from lawn fertilizers, chemical fertilizers from years gone by, and other common toxins. If you want plants (especially those you intend to consume) to have minimal to no chemicals and toxins, you want to go organic on all levels. 

Sometimes soil needs enriching.  Often the plants we're growing aren't native to our area. We have found organic compost and these organic plant foods to be a simple and nontoxic way to make our thumbs greener.