Place plants 18 to 24 inches apart with 30 inches between rows. Cauliflower grows best as a fall crop, but can also be grown in spring. For spring planting, sow seeds indoors 6 to 8 weeks before the last spring frost date and plant seedlings outdoors 2 to 4 weeks before the last spring frost date. For fall planting, plant a fall crop about 8 weeks before the first fall frost date, but after daytime temperatures are consistently below 75°F (24°C).
Cauliflower can be a challenge for beginning gardeners because it requires consistently cool temperatures in the 60°F (15°C) range. Too far below and the plant may not survive. Too much above and it can prematurely “button” (form small, button-sized heads) rather than forming a single, large head.
The soil must be very rich in organic matter, so it is very important to mix with compost before planting.
Important: Cauliflower does not like its growth interrupted. Changes, in the form of temperature, humidity, soil nutrition or insects, can cause plants to develop a head prematurely or destroy an existing one. In early spring, prepare to protect plants from frost with growing covers, if necessary. Extreme cold can stop growth and form buds. In summer, protect plants from the scorching sun, if necessary.
Ideally, heads will reach 6 to 8 inches in diameter. Cut the tops off the plant with a large knife. Make sure to leave a few leaves around the head to protect it. If the buds are too small, but have already started to open, they will not improve and should be harvested immediately.
