Brian the flowers of last year were planted in pre-fertilize potting soil and they did do great. I'm still not sure just how good the fertilized cabbage will do. I waded out to check it a few days ago and the head wasn't forming yet and there were a few bug spots on it. When the season is over I will take a picture of it and see if this was a good or bad idea, at least for cabbages. Your plants really look good.
John