Culture
Best grown in organically rich, fertile (high in nitrogen), consistently moist, well-composted, well-drained loams in full sun. Cauliflower is typically grown in the cool temperatures of spring and/or fall. Plants generally grow poorly when daytime temperatures consistently exceed 80 degrees F. In St. Louis, it is best to grow cauliflower for a late spring harvest and then to replant it 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 plants should be planted outside 1-2 weeks prior to the last spring frost date. Starting seed directly outdoors in spring (e.g., 4 weeks before last frost date) is not recommended because cauliflower is sensitive to frost. For fall harvest, sow seed indoors about July 1 and plant the seedlings outdoors in mid-August. Generally seedlings/transplants should be planted about 18" apart in rows that are 2-3' apart. 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 (Botrytis Group), commonly called cauliflower, is a cool weather vegetable that is grown for harvest of large tight heads of aborted white flower buds (curds). It is grown in St. Louis as an annual. Plants typically grow to 24-30" tall. Harvest cauliflower when the heads are firm and tight (often 6-8" across). Cauliflower is in the same species (Brassica oleracea) as a number of other cool season vegetables including kale, cabbage, Brussels sprouts, broccoli and kohlrabi. Botrytis Group also includes the similar Romanesco broccoli (spiraling cone-shaped heads of light green florets) and broccoflower (cauliflower with green heads).
Genus name comes from the classical Latin name for cabbage.
Specific epithet means of the vegetable garden.
Problems
Can be difficult to grow well in large part because it has little tolerance for heat, drought and cold. Potential insect problems include cabbage worms, 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.