Split heart is a condition of cabbages whereby a large split appears in the head.
When heads are mature, a sudden heavy rain may cause heads to crack or split wide open.
None. The exposed internal tissue soon becomes unusable. Harvest and salvage split heads as soon as possible after they are discovered.
Cabbage can be harvested anytime after the heads form. For highest yield, cut the cabbage heads when they are solid (firm to hand pressure) but before they crack or split. Foliar feeding at the first sign of trouble helps to harden the leaf tissue, but it is better to prevent trouble by watering regularly during drought.