Although it can be a challenge to grow, cauliflower will definitely reward your efforts. A plant with deep roots (pun intended), the Roman naturalist, Pliny, referred to the popularity of the plant in local cuisine as early as the 2nd century. A member of the brassica family, cauliflower is closely related to cabbage and broccoli (but you probably already guessed that). What you might not know is that, although most varieties of cauliflower are white in color, some can produce green, yellow, and even dark purple heads. Try your hand at growing this beautiful veggie: we believe even the most “green” of gardeners can have success.
The Purple of Sicily is a great heirloom variety of cauliflower that is easier to grow than other varieties, although it still requires proper care and a diligent eye to get proper head formation. Your hard work will be rewarded since this cauliflower grows beautiful, deep purple heads that turn green once cooked. Many consider the Purple of Sicily cauliflower’s flavor milder and sweeter than white types. This variety also offers some extra insect resistance, which comes in handy throughout the growing season.
Seed Depth: 1/4″
Space Between Plants: 18–24″
Space Between Rows: 24–30″
Germination Soil Temperature: 50–85°F, ideal 60–75°F
Days for Germination: 8–10
Sow Indoors: 4 to 6 weeks before average last frost date. For fall crop, 12 to 16 weeks before average first frost date. In mild climates, start in fall for harvest in late winter and early spring.
Sow Outdoors: 1 to 2 weeks before average last frost. For fall crop, 10 to 12 weeks before first fall frost. In USDA Zone 8 or warmer, sow in early fall for winter harvest.
Vegetative: Can be grown from cuttings, but we recommended that you start your plants from seed.
In most climates, it should be grown as a fall crop as it will taste and look best if it matures in cool weather. Temperatures between 60° and 75°F are ideal, with extreme heat or cold causing irregularities in the head formation known as buttoning. In warmer climates with only mild frosts, it will grow as a winter crop, especially if protected from nighttime lows with row covers and mulch.
Natural: Full sun.
Artificial: Grows well under fluorescent or LED lamps. Needs at least 8 hours of light per day; however, more is recommended.
Soil: Prefers a rich, loamy soil with high levels of organic matter and low salinity. A pH between 6.5 and 7.0 will keep plants healthy and nourished.
Soilless: Most soilless mixes will provide adequate nutrients and drainage for cauliflower starts.
Hydroponics: Thrives in media-based hydroponic systems. In one study, plants grown on pozzolana were shown to have the highest yield, with perlite and gravel media coming in second.
Aeroponics: Thrives in aeroponic systems but will require a significant amount of space.
Water: Requires moderate to high levels of water. Aim for 1 to 1.5″ per week, watering directly onto the roots below the plant. Watering from above can result in moisture collecting in the upward facing, cup-like leaves.
Nutrients: A heavy feeder, cauliflower will grow best if the soil is prepared with 2 to 3″ of organic compost before planting. After seedlings start to grow heads, work another couple inches of organic compost into the soil. Continue to work compost into the soil every few weeks following the appearance of heads until harvest.
Foliar: As cauliflower is susceptible to boron deficiencies, using a foliar spray of compost tea throughout the duration of the plant’s life cycle can help keep them healthy.
Mulching: Use mulch to help conserve soil moisture, particularly for younger plants.
Deficiency(s): A boron deficiency will cause cauliflower to turn brown. Amend soil with compost before planting to prevent this issue. To fix an issue that is already occurring, a dilute mixture of borax and water can be sprinkled on the earth around the plant’s stem, or try spraying the plant with liquid seaweed or compost tea. Black speck is a disorder that is also related to nutrient deficiency.
Rotation: A 3- or 4-year rotation away from plants in the brassica family is recommended to avoid pest and disease issues.
Companions: Grows well with beans, peas, beets, broccoli, Brussels sprout, celery, chard, sage, spinach, and oregano. Avoid nasturtium, radishes, tomato, potato, hot pepper, and strawberry.
Harvest: Should be harvested while heads are still dense and compact, after the center leaves covering the head begin to open and expose the purple florets. To harvest, use a sharp knife to cut the stalk about 1″ below the head. You can harvest leaves from plants before head formation begins, but only take a few or you risk stunting the plant’s development and taking nutrients away from head formation.
Storage: Will keep in the refrigerator for up to 2 weeks. Do not rinse or cut into pieces until ready to eat.
Fun Fact: This purple cauliflower is an heirloom variety that originated in Italy.
Preserve: The best method for preserving cauliflower is to freeze or pickle it. To freeze, cut head into florets, blanch, and place in freezer bags for up to a year for best flavor.
Prepare: A versatile vegetable, cauliflower can be eaten raw, steamed, boiled, fried, or roasted. To prepare, cut the head into florets and rinse. Add some oil and herbs to a pan or tray and mix in the florets to sauté or bake. Boiling or steaming is a quick way to cook florets, taking between 5 to 8 minutes. Florets should be soft but not mushy. Be aware that steaming and boiling will sap many of the nutrients from this plant, so baking or sautéing may be a healthier option. Leaves can be prepared similarly to other cooked greens, or eaten raw if picked when very young.
Nutritional: Cauliflower possesses vitamin(s) C, K, fiber, and various antioxidants such as beta-carotene that can benefit overall health. It also contains various minerals such as calcium, iron, copper, potassium, and manganese.
Medicinal: Like other members of the brassica family, cauliflower has been linked to the prevention of certain cancers, such as prostate, thanks to its content of the compound curcumin. Cauliflower has also been attributed with helping detox the body due to its glucosinolates, which can activate detoxification.
Try this simple Roasted Purple Cauliflower recipe to show off the amazing color of this tasty veggie.