You may have to order Corn Gluten Meal
HTH

Here is a link that might be useful: more info

My landscape business is Green Rochester landscaping, and am using corn gluten meal as an alternative to chemicals. I had a hard time finding it as well, I ended up buying it from my buddy whose family owns a dairy farm, there feed supplier sells it. I got a super sack witch I think is around 3000lbs and I think I spent $400, but the price depends on supply and demand and it is only going up. CGM helps repress weeds by preventing seeds from germinating; I read that it will prevent 40-60% of seeds from germinating. I donÂt know much about Bermuda grass but my guess is that it spreads by rhizomes underground roots so your grass should be fine. As far as the best season to apply CGM check out what kinds of weeds you have and find out when they germinate, and then apply before then. PS if you buy mail order bags that you are going to spent lots of money, check out feed suppliers.