Culture
Best grown in organically rich, consistently moist, well-composted, well-drained loams in full sun. Broccoli is typically grown in the cool temperatures of spring and/or fall. Plants generally grow poorly when daytime temperatures consistently exceed 80 degrees F. , and will not grow well in the heat of a St. Louis summer. It is best to grow broccoli for a late spring harvest and then replant in late summer for a fall harvest. For spring planting, sow seed indoors 6-8 weeks before the last spring frost date. In the alternative, transplants may be purchased from local nurseries. In either case, the seedlings/transplants should be planted outside 3 weeks prior to the last spring frost date. For fall harvest, sow seed indoors about July 1 and plant the seedlings outdoors in mid-August. Generally transplants (from home grown seed or from nurseries) should be planted about 18" apart in rows that are 2-3' apart. Plants typically mature to 24-30" tall. Keep plants consistently moist. Apply mulch around plants to protect the shallow roots, reduce weeds and retain soil moisture. Rotate crops to avoid soil borne diseases.
Noteworthy Characteristics
Brassica oleracea (Italica Group), commonly called broccoli, is a cool weather vegetable that is grown for harvest of large, tight, terminal heads of green flower buds at the ends of thick edible stems. It is grown in St. Louis as an annual. Plants typically grow to 18-30" tall. Harvest broccoli promptly as soon as the heads are firm and tight and before any of the buds begin to open. Cut the stem about 5-6" below the base of the head. Broccoli is in the same species (Brassica oleracea) as a number of other cool season vegetables including kale, cabbage, Brussels sprouts, cauliflower and kohlrabi.
Genus name comes from the classical Latin name for cabbage.
Specific epithet means of vegetable gardens.
Problems
Potential insect problems include cabbageworms, cabbage loopers, flea beetles, caterpillars, thrips, slugs and aphids. Root maggots may be a problem in some areas. Watch for leaf spots, blackleg, black rot and yellows.