Cauliflower plants should be kept growing vigorously from the seedling stage through harvest. Any interruption (extreme cold, heat, drought or plant damage) can abort development of the edible portion. Large plants that never develop a head are extremely disappointing. Cauliflower must have a consistent and ample supply of soil moisture. Side-dress nitrogen fertilizer when the plants are half grown.
When the head begins to form (shows 2 to 3 inches of white curd at the growing point), it is ready to blanch. Tie the outer leaves together over the center of the plant to protect the had from sunburn and to keep it from turning green and developing an off-flavor. The variety Self-Blanche is named for its natural tendency to curl its leaves over its head. Several other varieties possess this trait, especially when maturing in the fall. Under cool conditions, these varieties blanch very well and tying is unnecessary.
Cauliflower is best started from transplants for both spring and fall crops. Do not transplant sooner than 2 to 3 weeks before the average frost-free date in the spring. Cauliflower is more sensitive to the cold than its cabbage-family relatives. It is important to start cauliflower early enough that it matures before the heat of the summer but not so early that it is injured by the cold. In some seasons, that compromise may be almost impossible to achieve. Transplant autumn cauliflower about the same time as fall cabbage. Use starter fertilizer when transplanting. Start the transplants so that they grow actively until transplanting and never cease growth. Always use young, active transplants. Never buy stunted plants started in flats and held too long before transplanting; results with inferior plants are almost always disappointing.
Space plants 18 to 24 inches apart in the row. Use the wider spacing for fall plantings. Apply one cup of starter fertilizer solution around the root zone of each seedling.
Additional pests and problems that may affect this plant: