The Structure of Brassica Plants

Planting

• Brassica crops have small seeds that are planted 1/4 inch deep in the soil. Plant them in early spring as soon as the soil is soft enough to work and again in midsummer, if desired, for a fall crop. Many gardeners prefer to start seeds indoors or set out nursery transplants in the spring for faster growth. The seeds germinate quickly -- usually within four to seven days -- when soil temperatures are between 45 and 70 degrees Fahrenheit.

Plant Growth

• Brassicas grow fairly quickly, but vary in their structure, depending on the plant. Broccoli and cauliflower, for example, produce edible flowering stalks. Broccoli and cauliflower heads are actually immature flowers. If you allow these plants to continue to grow, small yellow flowers will appear on the tops of the heads. Kale and collards produce leafy greens on sturdy stalks, while cabbage and Brussels sprouts form tight, leafy heads.

Growing Conditions

• All brassica plants prefer rich, well-drained soil and cool, slightly moist conditions. They grow in full sun or filtered shade during hot weather. Brassica crops may go to seed early or become woody in hot, dry conditions. Install floating row covers and rotate crops to thwart the many insect pests that feed on brassicas.

Harvest

• Cut broccoli heads with a sharp knife before they go to seed. The plant will regrow new side shoots for later harvests. Cut cabbage heads when they are 10 to 12 inches across. Wrap leaves around cauliflower heads when they are 2 to 4 inches across to blanch the vegetable, causing it to turn white. Secure the leaves with a rubber band and leave it in place for several days or up to one week.