Cauliflower

Cauliflower (Brassica oleracea var. botrytis) is the most temperature-sensitive brassica in the home garden. Heat at the wrong moment - specifically during head formation - produces loose, ricey curds or no head at all. Get the timing right and you have a crop that retails for $3.50-5.00/lb for standard white heads and $5-8/lb for orange, purple, or romanesco types (USDA AMS Specialty Crop Market News, 2023). Get the timing wrong and you have an expensive ornamental.

What you’re choosing between

White cauliflower is what most grocery stores carry. The colored types are where the home garden advantage is clearest.

Orange cauliflower (cultivars like Cheddar) gets its color from beta-carotene accumulation. Sweeter than white and holds color through cooking better than purple. Commands a noticeable price premium at farmers markets.

Purple cauliflower (Graffiti, Violet Queen) turns green when cooked - the anthocyanins are heat-sensitive. Best eaten raw or barely steamed. Retail price at specialty stores runs $5-8/lb.

Romanesco is technically a cauliflower. Its lime-green spiral structure sells out at farmers markets. It’s also significantly harder to grow - heat-sensitive, slow to mature, and unforgiving of timing errors. Save it for your second season with cauliflower.

The ROI case

A $3.49 packet contains 200-300 seeds. At $3.50/lb retail for a 2 lb head, you’re looking at $7/plant in grocery value from $0.02 in seed cost. The catch is failure risk - an unexpected heat spike during heading ruins an entire planting. This is not a low-variance crop the way kale or collards are.

Growing requirements

Cauliflower needs cool temperatures throughout its growth cycle, especially during head initiation. Temperatures above 80°F for more than a few days during heading cause curd problems. Below 40°F for extended periods during early plant development trigger buttoning - tiny premature heads that never develop properly (Cornell Cooperative Extension, Cauliflower Production, 2018).

The target window is 60-75°F during daylight for the heading period. In most of the US: spring (transplant 4-6 weeks before last frost, harvest before summer) or fall (transplant in late summer so heading occurs in September-October as temperatures drop).

Soil pH 6.0-7.0. Cauliflower is a heavier feeder than most brassicas. Work in 2-3 inches of compost before transplanting; apply nitrogen fertilizer every 3-4 weeks until heads begin forming. Nitrogen-deficient plants produce small, loose heads.

Space transplants 18-24 inches apart.

Blanching white varieties: When the head reaches golf ball size, pull outer leaves over the curd and secure with a rubber band. This blocks sunlight and keeps the head white and mild. Orange and purple types don’t need it.

What goes wrong

Buttoning - tiny premature heads on young plants - results from cold stress below 40°F during early development, or from transplanting root-bound starts. Use young, actively growing transplants.

Ricey or loose curds come from heat during heading. Harvest what you have and use it; there’s no fixing it.

Imported cabbageworm (Pieris rapae) and cabbage looper (Trichoplusia ni) are the primary caterpillar pests. Bacillus thuringiensis var. kurstaki (Bt) applied weekly while caterpillars are small is effective. Row cover prevents egg-laying.

Clubroot (Plasmodiophora brassicae) causes swollen, distorted roots and wilting. Raise soil pH above 7.2 by liming; rotate brassicas out of infected beds for 4+ years (Penn State Extension, Crucifer Diseases, 2019).

Harvest and storage

Cut the head when it’s compact and firm, before any separation between curds begins. 2 lb is a solid target. Once curds begin separating or the surface looks grainy, quality drops fast - harvest immediately.

Refrigerates for 1-2 weeks. Blanch and freeze for up to 8 months.

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Related crops: Broccoli, Kale

Related reading: Soil pH by Crop - brassica pH requirements directly affect clubroot pressure and nutrient availability