Cut and Come Again Cabbage
One of the neat things about spring cabbage is this: cut the first heads high on the stem, and a cluster of nice-sized secondary heads will grow from the stump, somewhat like giant, loosely curled brussels sprouts. You can grow cut and come again cabbage in the fall, too, though new growth slows to a crawl as fall turns to winter.
The cut and come again cabbage technique works best in early summer, practiced on plants that still have some spring vigor left in them. In hotter weather, the cabbage will cut and come again, but the secondary heads may be below ground, as pale nubby heads encrusted with soil. Interesting but inedible without a lot of washing.
This is a unique aspect of growing garden cabbage that should be more widely practiced. When things go well, you can double per plant productivity by growing cabbage cut-and-come-again style.