Growing Cauliflower from Seed

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By Nancy Pierson Farris, South Carolina

Growing cauliflower from seed brings this healthy vegetable from garden to table.

Cauliflower can serve as the focal point for a centerpiece or it can serve as a low calorie, low carbohydrate substitute for mashed potatoes. I enjoy it raw in my lunch salad, or steamed with a bit of butter or a sprinkle of Parmesan cheese.

The edible portion of cauliflower is fully exposed to any chemical used to control cabbage worms or other invading pests. By growing cauliflower from seed, I control what is sprayed on the plant.

Cauliflower will grow in spring or fall — succession planting in either season will provide fresh heads for several weeks.

The best curd forms during cool weather, though if young plants are exposed to extreme cold, the plant will form buttons rather than large, succulent heads. When exposed to high temperatures, the plant will form small, bitter, discolored heads. In my area of South Carolina, summer heat brings a quick end to spring cauliflower. When summer abates, however, I can grow lovely cauliflower during the fall months. In other areas, springtime allows for planting, although harvest must be done by the peak summer heat. Cauliflower is definitely on the winter vegetables list.

For my fall plantings, I start cole crops on a screened porch, growing seedlings indoors to protect from insects and hot summer sun. I pot up cauliflower seedlings into four-inch pots. I have fluorescent lights hung a few inches above the plants, and I feed them weekly with fish emulsion.

I put cabbage and broccoli plants into the garden about six to eight weeks after sowing the flats. I have had best results with cauliflower if I wait until seedlings are about 12 weeks old.

I set my fall cole crops into space that has already born a spring crop. Since cauliflower requires a lot of nitrogen, I like to place them into a row that has been vacated by a legume, which has fixed nitrogen in the soil. After tilling the area, I spread compost into a furrow, cover it with two inches of soil, then set the young plants about 18 to 20 inches apart.

The large leaves of cauliflower transpire copiously, so plants require a steady supply of moisture. The USDA recommends an inch to an inch and a half of water per week.

Initially, all cole crops look alike. I label flats and pots, but sometimes a seed has floated over to settle with a cousin. Or a seedling gets into the wrong pot. What I thought was a cauliflower may form a cabbage head near the ground, rather than growing large leaves. Or a green curd forms in that nest of leaves, identifying the plant as a broccoli.

I grow self-blanching cauliflower, which makes a floret of leaves to protect the curd from sunlight. I gently open that floret to find a tiny white curd. Then I know I have cauliflower.

All cole crops attract cabbage moths, which lay eggs on the underside of leaves. I check my plants in early morning, crush any masses of yellow eggs, and pick off any green worms I see. I use Bacillus thurengiensis as a control. It is toxic only to worms. It is available in either dust or liquid. Clemson agents recommend using the spray, because dust can cling to bees, those faithful pollinators in the garden.

I start harvesting as soon as curds are a few inches across, and continue cutting them as needed. Unlike broccoli, cauliflower does not make side shoots, so after harvesting a head, I pull the plant and toss it into the goat pen. The leaves are edible, but we prefer collards for our greens.

If cauliflower curd begins to separate or turn yellow, I harvest them immediately. They will keep in the refrigerator for a couple of weeks. If I have many, I cook them briefly and pack into containers for freezing: food preservation which works great for garden produce.

If grown in fall, cauliflower withstands light frost. When night temperatures drop below 30°F, I cover each plant with a basket.

Have you tried growing cauliflower from seed? Do you have any tips to share?

Originally published in the March/April 2016 issue of Countryside & Small Stock Journal.