The most temperamental member of cabbage family crops, cauliflower grows into a large, broad plant before producing a crisp central head. Growing cauliflower is not recommended in spring unless you live in a climate with consistently cool summers, because temperatures above 80 degrees Fahrenheit during head formation causes the heads to become small and of poor texture.
In most areas cauliflower is best grown as a fall crop, with seeds started indoors in early summer. If you live where winter temperatures stay above 20 degrees, you can grow selected cauliflower varieties through winter for harvest in spring.
Types of Cauliflower
Cauliflower varieties vary in growth rate and color. Almost all common varieties are hybrids.
Early cauliflower varieties such as ‘Snow Crown,’ ‘Denali’ and green-headed ‘Panther’ mature about 70 to 80 days after planting, so they are a good choice for climates where fall weather does not last long. However, the heads of early cauliflower varieties are not as large, dense and sweet as those that mature later.
Main-season cauliflower varieties need more than 80 days after transplanting to mature, but the large heads are worth the wait. In addition to growing cauliflower varieties with white heads such as ‘Candid Charm’ and ‘Skywalker,’ try purple cauliflower such as ‘Graffiti’ or ‘Orange Burst’ orange cauliflower, which has more vitamin A than other types of cauliflower.
How to Plant Cauliflower
Unlike cabbage and broccoli, cauliflower can rarely be grown successfully from plants set out in spring. Hot weather that arrives just as spring-planted cauliflower heads up ruins its flavor and texture, and the plants become magnets for insects.
A much better planting schedule is to wait until late spring or early summer to start cauliflower seeds. Recommended seeding dates for a few locations include May 30 in Maine and Ontario, June 15 in New York, July 1 in Kentucky, July 15 in Alabama, and October 15 in Arizona. Harden off the seedlings before setting them out in well-prepared soil, and plan to cover them with lightweight row cover or tulle to exclude insect pests.
Cauliflower plants are heavy feeders that demand moist, fertile soil with a pH between 6.0 and 7.0. Mix in a generous application of a balanced organic fertilizer before planting, and allow at least 24 inches between plants (because tight spacing will lead to small heads). Use a biodegradable mulch of grass clippings or coarse compost to insulate the roots from summer heat.
For recommended planting dates for your local climate — and to design your garden beds — try our Vegetable Garden Planner.
Featherweight row cover held aloft with hoops or stakes is the easiest way to protect actively growing cauliflower plants from grasshoppers and other summer insects.
As the plants grow, drench them with a high nitrogen fertilizer such as fish emulsion every two weeks. Cauliflower plants stay low to the ground, and never grow tall.
Harvesting and Storing Cauliflower
Use a sharp knife to cut heads from the plants when they are the size you want, but before they become off-color or rice-like in texture. Refrigerate harvested cauliflower immediately. Cauliflower will keep in the refrigerator for several weeks, or you can blanch and freeze the florets. Cauliflower plants produce only one head, so they can be pulled and composted after the crop has been harvested.
As biennials, cauliflower plants produce yellow flowers followed by elongated seedpods in their second year. When the seedpods dry to tan, gather them in a paper bag, and allow them to dry indoors for a week. Shatter the dry pods and collect the largest seeds for replanting. Under good conditions, cauliflower seeds will store up to three years.
Keep in mind that the overwhelming majority of cauliflower varieties are hybrids, which will not breed true from saved seed. If you do plant to save seed, ensure you’re not planting a hybrid variety.
For growing advice for many more garden crops, check out our complete Crops at a Glance Guide.
Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.