I have them on 18/6 and I have not fed them anything except the admendments I made to the soil. Well i added a very little molasses and coconut water to a couple of waterings. Straw or any type of mulch seems to be real beneficial to the living soil. There are some types of living mulch that can be even more beneficial... I think clover... I have to look into it. I am going to top dress in some gypsym, neem, alfalfa meal, guano(I know not sustainable but I have it), and fish by day 21.