Here are my tips for growing great cabbage:

Site, soil type:

Cabbage needs very fertile soil.     It likes moisture and coolness.

Plant after a legume for extra nitrogen.

It does well in partial shade when the weather is hotter.

Planting requirements:

Start indoors 6 weeks before planting outside.     Plant outside after temperatures won’t go below 45 degrees.

Set transplants 1” deeper in the ground than they were in the container.

Nutrition/Fertilizer needs:

It is a heavy feeder.  Add ½ to 1 cup of complete organic fertilizer per plant.

Foliar feed with kelp meal tea for extra nutrition.

Water needs:

Keep soil wet constantly.   Cut back on water near maturity to avoid heads splitting.

Other tips:

Aromatic herbs planted nearby will deter cabbage worms.     Dill improves growth and health.

A lightweight row cover will exclude cabbage worms.

Use Bt for the elimination of cabbage worms.

Create a Bt bait by mixing wheat bran into Bt.  Add 1 tablespoon of molasses.  Spread around the base of plants.

Red cabbage seems to be more resistant to pests.

Time crops so they mature in cool weather for better flavor.

Mulch with leaves and manure to keep base of plants cool and moist.

Splitting may be avoided by slowing plants growth near maturity.  Do this by cultivating near the plants and chopping the roots back.