Planting and Growing Cauliflower
Cauliflower thrives in cool temperatures, so it's a good pick for a fall garden. Here's how to grow this superfood in your backyard.
The real trick with cauliflower is that you have to blanch the heads to make them white. Blanching involves tying the outer leaves over the developing head—when it’s roughly 2 to 3 inches across. It also must go in the ground early enough so it matures before summer heat arrives (temps over 80 F). If that’s not enough to deal with, you need to keep an eye out for cabbage worms, which feast on leaves and the head.
Johnny’s Selected Seeds
Sun-loving cauliflower is in the same family as broccoli, cabbage, brussels sprouts and turnips, that whole clan of cool-season leafy green vegetables that thrive in the garden before and after summer's heat.
Cauliflower has been cultivated for centuries. It appeared in its modern form sometime between the 500s and 1500s AD on the Mediterranean island of Cyprus, thanks to some fancy selective breeding of wild cabbages by humans. Cauliflower then spread to Turkey, Egypt, Italy, Spain, and Northwestern Europe. The cauliflower plant came to the New World with Europeans in the 1700s.
Planting cauliflower and growing cauliflower in fall gardens is an American tradition. We eat this extremely healthy vegetable in Indian curries, North African stews, cheesy casseroles and raw on veggie platters. Cauliflower is so packed with nutrients that it's considered a superfood.
Cauliflower isn't the easiest veggie to grow. It's super-sensitive to temperature changes and needs cool weather to thrive. But if you give it what it needs, you can grow this superfood in your garden.
The dense, mounded head of cauliflower is called the curd. That's the part you eat, and it grows on the main stalk of the plant. You'll get the biggest curds when the plant is grown in cool temperatures, between 50 and 70 degrees. All parts of the plant are edible, but most people are growing cauliflower for its head.
Hot weather makes cauliflower bolt — mature quickly and start to bloom — which means it will stop making curds and begin making flowers and seeds. That ends its value as a food-producing plant. So as soon the temperatures warm up, cauliflower is history.
Some types of cauliflower are good for spring planting because they grow fast enough to produce curds before the heat of summer arrives. Planting cauliflower in mid-summer for a fall harvest is the best choice for most varieties.
Most cauliflower has white curds, or heads, but there are varieties that produce green, yellow, and purple heads. You'll need to blanch some varieties of white cauliflower to turn them white. You do this by covering the head from the sun for a few days before harvesting. Other varieties are self-blanching and don't need your help to turn snow white.
In cool climates, like Zone 4 or lower, you can grow cauliflower all summer. And in warm climates, like Zone 8 or warmer, where it seldom freezes, you can grow cauliflower all winter. Cauliflower is slow-growing, needing 100 days (3 months) to reach maturity, so you need to start it early to give it time to make heads.
Here's what you need to know to grow cauliflower at home.
Botanical Name: Brassica oleracea
Common Name: Cauliflower
Bloom Time: Spring
Plant Type: Vegetable biennial, but grown as an annual
Hardiness Zones: 2 to 11
Start cauliflower from seeds, indoors, six weeks before your last frost date. Since cauliflower doesn't like having its roots disturbed, start the seeds in peat or paper pots that will let you transplant the whole pot into the ground.
Transplant the seedling to a sunny spot in the garden when they are 4 to 6 inches tall. You can also buy transplants from a nursery at this point, too.
Space them 18 to 34 inches apart. You want to give their outer leaves plenty of room to grow and spread.
To deter pests and attract beneficial insects, plant with cauliflower companion plants like beans.
Caring for Cauliflower
Cauliflower plants grow best in full sun. Make sure they get at least 6 hours of light per day.
Give them 1 to 2 inches of water a week if no rain falls. They need well-drained soil with consistent moisture to grow nice, big heads.
Cauliflower likes cool weather but cannot tolerate a frost. And it suffers when temperatures pass 80 degrees, which is why you have to plant it before or after the heat of summer.
Mulch the plants to keep the soil cool and its roots moist.
Fertilize every 2 to 4 weeks. Because cauliflower takes so long to mature, up to 3 months for some varieties, it will need some supplemental nutrition from you.
Left on its own, cauliflower heads are usually yellowish-brown. If you want yours to be white, you'll need to blanch it. Begin blanching cauliflower when the heads are the size of a large chicken egg. To blanch, fold the larger leaves of the plant over the head and tie them lightly in place. The goal is to block the sunlight from the head but leave room for it to continue growing.
Once you tie the leaves, keep the head dry and keep an eye out for insects hiding in the tied leaves.
Another way to blanch cauliflower: Just put a bucket over a plant. Don't want to be bothered with blanching? Plant a colored variety of cauliflower, or a self-blanching variety that doesn't need your help to achieve its peak color.
Most cauliflower need 2 months to mature from the time you put transplants in the garden. Some varieties mature more quickly, others more slowly.
Harvest when heads reach the size you want and the buds are still tight. If you leave the heads on the stalk too long, their flowers open and its taste will change.
If you can't cook them right away, you can harvest and freeze cauliflower heads.
Pests and Diseases
Cauliflower is susceptible to all the same pests as their cabbage kin, including:
- Cabbage maggots, cabbage loopers, and cabbage worms — nasty cauliflower-munching bugs you can pull off by hand.
- Aphids. They'll suck the sap out of leaves and kill the plant. Spray with organic pest killer.
- Flea beetles will eat the leaves of your plants. Pull them off by hand and crush them.
- Black rot — yellow, V-shaped lesions appear on the leaf and cause it to wilt and die. It's caused by overwatering, underwatering or too much fertilizer.
- Leaf tip dieback and distortion — leaf death caused by a nutritional deficiency. Fertilize with sea kelp to put enough boron in the soil to keep your cauliflower nourished and healthy.
Recommended Cauliflower Varieties
Ravishing purple heads with a buttery-sweet flavor. It contains the same antioxidants found in red wine, so it's more nutritious than white cauliflower.
'White Corona Hybrid'
This speedy growing cauliflower will produce a head in just a month after transplanting seedlings. You can get a potful of superfood in record time.
This variety is more heat-tolerant than some others and produces large orange heads with a buttery, nutty flavor. Matures in as little as two months, so it's a good pick when you want a fast crop.
Produces small, succulent florets that look a little like broccoli but taste like sweet cauliflower. Plants mature in just 85 days, a few weeks faster than other varieties, so it's a good pick if you have a shorter growing season.
Heirloom variety that produces classic 6-inch white heads.