Throughout the United States.
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Set transplants so the top of their rootball is even with the garden soil.
Spacing: Cabbage, cauliflower, and broccoli--15 to 24 inches apart; brussels sprouts--30 to 36 inches apart; kohlrabi--4 to 6 inches apart; kale and collards--8 to 12 inches apart. Or, sow seeds ½ to 1 inch deep and 1 inch apart. Thin according to the spacings listed above when the seedlings have 2 or 3 leaves.
Any good garden soil. pH 6.0 to 7.0.
At planting time use 2 to 4 pounds of 10-10-10 fertilizer per 100 square feet, or 1 pound per 25-foot row. Side-dress every 3 to 4 weeks with 1 pound per 25-foot row, or 1 to 2 tablespoons per plant.
How much: Apply enough water at each irrigation to wet the soil 8 to 10 inches deep.
How often: Water when the soil 1 inch deep is barely moist.
Broccoli: When the buds are still tight, before they open into yellow flowers. Smaller heads will grow along the stem after the first head is harvested.
Brussels sprouts: Pick sprouts from the bottom up when they are about 1 inch in diameter and still tight. Remove the leaves as you pick.
Cabbage: Cut just below the head when firm and before it cracks.
Chinese cabbage: Cut the entire head when it is 12 to 16 inches tall.
Cauliflower: Cut when the heads are 6 to 8 inches in diameter with tight curds.
Collards and kale: Pick the leaves when the plant is 1 foot tall. Or the entire plant may be harvested. Kale flavor improves after a freeze.
Kohlrabi: Harvest when the bulb is 2 to 3 inches in diameter.
