Harvest cabbage as soon as the heads form. Pull them up with the roots attached, discarding the loose outer leaves.
If the cabbage is stored in the house there may be an odor problem. The plants can be stored in a pit, trench or outdoor root cellar. In cellars, hang them by their roots, wrap them in newspaper tied with string or place them in crates.
Store cabbage at temperatures near 32 degrees in moderately moist air.