Cauliflower
Cauliflower is a classic addition to the vegetable garden. The vegetable is both nutritionally dense and appealing to the eye, especially the brightly colored varieties.
Cauliflower (Brassica oleracea var. botrytis) is a member of the same species as kale, cabbage, kohlrabi, and Brussels sprouts. These plants are all brassicas, or cole crops, meaning that they share many characteristics and growth habits.
Planting and Care
Cauliflower is a cool-season vegetable with planting dates that vary by location. Plant in North Florida between late August and January, and from September through January in Central and South Florida.
You can choose to purchase transplants, start your plants in a greenhouse, or seed directly. The most foolproof method is growing from transplants. Either way, you should consider what characteristics you would like to see in your crop. Some cultivars boast early maturity, some offer vibrantly colored heads (orange, green, or purple), and others are self-blanching. Blanching is a unique part of cauliflower's growing process that involves protecting the head from the sun (more details on this later in the article). If the head is exposed to excess sunlight, it will become discolored and may not have the best flavor. The advantage of self-blanching cultivars is that the leaves surrounding the head will curve around it as the plant grows, naturally shading the head.
If starting your plants from seed, plant them at a depth of ¼–½ of an inch with the plants spaced 12 to 18 inches apart. Ideal row spacing depends on variety, but they can be as tight as 12 inches or as far as 40 inches apart. You can apply fertilizer before, during, or soon after planting. You should also aim for a soil pH between 6.0 and 7.0. Your local county Extension agents can help with selecting the best soil amendments based on your soil type.
Romanesco cauliflower is uniquely shaped, but can be prepared the same as regular cauliflower. Photo by Preston Keres, USDA.
Apply fertilizer as needed throughout the growing season, especially if the plant has endured heavy rains. However, be sure to test your soil fertility before applying fertilizer to prevent excess application. The experts at your local county Extension office can also assist with soil testing.
Premature head formation may occur (called "buttoning") if the plant becomes nutrient deficient or experiences a lack of irrigation. Proper care is important because a buttoned head will never reach its full size. Buttoning can also occur if the plant experiences 10 or more days between 35- and 50-degrees Fahrenheit. Transplants should be grown at 55 degrees Fahrenheit or higher to prevent this.
Unfortunately, there are many pests you may encounter: aphids, leaf miners, cabbage loopers, diamond-back moth larva, imported cabbage worm, grasshoppers, cutworms, wireworms, flea beetles, and mole crickets. Potential diseases also abound, and include damping-off, wire-stem, downy mildew, leafspot, black rot, blackleg, yellow sclerotinia, anthracnose, and bacterial soft rot. If you spot any sign of pest activity or disease, contact your county Extension office for treatment advice.
Blanching your cauliflower
Keep an eye on your cauliflower plants once they begin developing the head, sometimes called a "curd." Once the head is approximately three inches in diameter or the size of a teacup, you should blanch it.
Normally cut off by the time you see them in the grocery store, a few tightly curling leaves of a self-blanching cauliflower are visible in this photo. Photo by Preston Keres, USDA
The process involves pulling the longest leaves over the cauliflower head and securing them with soft twine, raffia, tape, or rubber bands. Make sure it is secure enough to block all light from reaching the curd, but not so tight that leaves are damaged. This step is especially necessary for white-colored varieties, which are highly susceptible to sunburn.
If you are growing many plants, it may be helpful to use color-coded ties based on the day you blanch them. That way you will know which to check first for maturity. Your plants may not reach this stage all at once, so keep checking until you have blanched them all. You can generally skip this step if you are growing a self-blanching variety, provided they are growing as they should.
Harvesting
It's time to harvest your cauliflower when the heads are fully developed but have not begun to separate yet. The head is still fine to consume if it has separated, but a compact curd is preferred. Keep in mind that heads will develop much faster in warm weather. Start by checking the first plants you blanched and then work your way through them all as they mature—this is where those color markers come in handy!
Cauliflower needs prompt refrigeration after harvesting. The heads are sensitive, and refrigeration will keep them freshest. Consume or preserve them as soon as you can to prevent spoilage.