Cauliflower plants can grow quite large, and it seems that the larger the plant the greater our expectations for the fruit or vegetable it produces. How disappointing then when a cauliflower plant fails to produce any heads at all. There are a few reasons for such a failure, and each is easily remedied with some more careful planning and a little extra care the next time around.
Cauliflower is extremely sensitive to any stress early in its development. Stress that results from temperature fluctuations or extremes, from inconsistent watering or from stalls in growth will threaten the plant’s ability to develop or to fully develop the cauliflower heads.
In general, the soil should be moist to a depth of 6 inches. Use drip irrigation set to a timer to achieve consistent and thorough irrigation. Cauliflower needs consistent moisture if the plants are to develop full heads. Cauliflower needs more water the later you plant it. Cauliflower plants whose growth continues into the warmer parts of the year are going to require more water than those grown in regions where there is enough time between that cool early spring weather and the warmer early summer weather that threatens a cauliflower’s development.
Cauliflower is a cool-season crop. This means that it doesn’t tolerate warm temperatures and must be planted early enough in the season to mature before warm weather arrives. In fact, many varieties of cauliflower must be blanched, a process in which the leaves of the plant are tied over the heads to protect them from sun damage just before harvest. On the other hand, too much cold weather before or after transplanting will also stunt the transplant’s growth and will affect its ability to develop mature heads later on.
Soil and Fertilizer
The soil may also be a problem. Because cauliflower is such a heavy feeder, the quality of the soil is very important for head development. If the soil is very poor to begin with, and you don’t do much in the way of amending it, it’s unlikely that you’ll end up with big, white, round and beautiful cauliflower heads. Amend the soil with compost, till it until it’s nice and crumbly and apply a general 5-10-10 fertilizer at a rate of 3 lbs. per 100 square feet before planting your transplants, as the Clemson Cooperative Extension recommends. It’s also important to side-dress the plants with nitrogen once they’re established, or after three to four weeks, at a rate of 1 lb. per 100 feet of row.