Follow the guidelines for success growing cauliflower.
Cauliflower is a cool-season vegetable and is more difficult to grow than other members of the cabbage family.
When To Plant
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, around mid to late-July.
- 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.
Spacing & Depth
- Space plants 18 to 24 inches apart in the row.
- Use the wider spacing for fall plantings.
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 head 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.
Common Problems Growing Cauliflower
- Cabbage worms
- Black rot
If growth is interrupted, the heads may not develop or may develop poorly. Growth can be interrupted by plants' being held too long, causing hardening and cessation of growth before transplanting; by too much chilling before or after transplanting; or by drought.
The cauliflower head's curd develops rapidly under proper growing conditions. It grows 6 to 8 inches in diameter and is ready to harvest within 7 to 12 days after blanching begins. The mature heads should be compact, firm and white. Harvest the heads by cutting the main stem. Leave a few green outer leaves attached to protect the heads. Cut the heads before they become overmature and develop a coarse, "ricey" appearance. Once individual florets can be seen, quality deteriorates rapidly. Because cauliflower does not ordinarily develop side shoots, plants may be disposed of or composted after heads are harvested.
Questions & Answers
Q. What causes leaves in the head and separation of the head into loose, smaller curds?
A. These conditions are caused when cauliflower matures during hot weather. Try to time maturity dates of cauliflower to minimize the risk of extreme heat as the heads form.
Q. Why does my late cauliflower fail to make satisfactory heads?
A. Late plantings are sometimes difficult to grow. The young plants often do not become well established under hot, dry summer conditions. Give the plants ample water and do not plant late cauliflower plants too close together.
Q. Is purple cauliflower grown in the same way as regular cauliflower?
A. Purple cauliflower is actually a type of broccoli that is purple. It resembles cauliflower in overall appearance and does not require blanching. The purple head turns green when cooked.
Q. What causes browning of the curd?
A. This condition is caused by downy mildew. Downy mildew, which is brought on by wet conditions, can be controlled through the use of a suggested fungicide. Raised-bed culture and any other cultural measures that encourage good soil and air drainage also help minimize the risk from this disease.