Cabbage does best in humus-rich soil amended with composted manure. Mix ½ cup complete organic fertilizer into the soil beneath each transplant. If growth slows, side dress with a little more balanced organic fertilizer. Heads of early varieties can split from over-maturity, rapid growth after heavy rain, or irrigation after dry spells. Splits can be delayed by twisting the plant or cultivating deeply next to plants in order to break roots and slow growth. Fall and winter varieties stand in the garden longer without splitting. If direct sown, add 20-25 days to the maturity date.