Molasses doesn't feed the plant per say, it feeds the bacteria in the soil which in return feed the plant. You can lock out your plants by using it if you don't have plenty of living bacteria in the ground they are what will eat the sugars and excrement food for your plant at a tourible ph. This usually works good in big outdoor controlled grows that are using super soil, or just good soil full of organics and worm castings. I never add molasses directly to the soil, but rather in a tea where I'm growing beneficial bacteria then into the ground. (This is only how I do it) other successful growers probably have different methods.