Purple Express needs full sun and rich, well-drained soil to produce firm, sweet heads. To avoid stunting growth, don’t let seedlings get crowded before thinning or transplanting. Keep weeded and evenly watered. Feed monthly with fish emulsion or an all-purpose fertilizer. Use non-toxic B.T. (Bacillus thuringiensis) for caterpillar pests. Floating row covers provide a good barrier method to exclude pests. Remove covers when heads begin to form.
Cut the whole cabbage at ground level only when these tall, vase-shaped heads are very solid and about 6-8 inches in diameter.