Along with its brethren broccoli, Brussels sprouts, collards, kale and kohlrabi, cauliflower is a member of the Cole family (Brassica oleracea). While all of these veggies require cool temperatures for maximum production, cauliflower is by far the most temperamental, leading to a number of issues with this crop such as cauliflower ricing, wherein a fuzzy growth appears on cauliflower heads.
What is Ricing in Cole Crops?
Cauliflower flourishes in temperatures of around 60 F. (15 C.). Young cauliflower plants are extremely sensitive to stressors, whether they are temperature fluxes or irrigation issues. As with all plants, any extremes in their environment may result in a low yield, premature crop, susceptibility to disease, insect invasion and many other disorders. Cauliflower, especially, has a thin balance between leaf and head growth, making it vulnerable to a number of disorders including ricing in this cole crop.
Cauliflower ricing is when the head, or cauliflower curd, looks like velvet. Some people describe it as a fuzzy growth on cauliflower.
What Causes Fuzzy Cauliflower Heads?
As mentioned, cauliflower is much more at risk for cole crop disorders than its cousins due to stressors. Because it enjoys moderately warm temperatures, the effects of higher temperatures during its growing season can affect the curd adversely. Timing of planting is crucial. This goes hand in hand with selecting the correct variety of cauliflower to plant in your region.
How to Prevent Cauliflower Ricing
Seeds can be directly sown in the garden, but again, check the germination to maturation dates on the package. You may need to start seed indoors early, depending upon the last expected frost date in your area, to give the plant a jump start.
Plants can be transplanted after the last killing frost in the spring. Cold temperature will slow growth and even damage the transplants. Transplants should be less than 4 inches tall with vigorous root systems. Water the transplants as needed to provide them with at least one inch of water per week.
Lack of nitrogen has also been shown to be a contributing factor, resulting in fuzzy cauliflower heads. Side dress the transplants after their third week with nitrogen every two weeks for a total of three side dressings. If the soil is especially low in clay and organic content, one or two of these side dressings should include an equivalent amount of potassium.
As with most veggies, cauliflower needs at least six hours of full sun per day. Plant the cauliflower in fertile, well-drained, moisture retentive soil with lots of rich organic content. Optimally, the soil pH should be between 6.5 and 6.8. Amend soil with nitrogen rich blood meal, cottonseed meal, or composted manure or work in a time released food like 14-14-14 into the soil prior to planting. Apply 1 to 1 ½ inches of water per week.
To prevent ricing in cauliflower, ensure adequate moisture, avoid stressful temperature fluxes by planting at the correct time, and augment the soil with additional nitrogen if need be. In the case of temperature spikes, you may want to shade the plants, or conversely, use row covers or the like in the case of cooler than normal temperatures.