The nubs on the broccoli are actually tightly clustered flower buds. Harvest the head after the flower buds begin to swell, but before they actually open.
PHOTO: DAVID CAVAGNARO
Learn about this nutritious vegetable and the best broccoli varieties to grow in your garden. See the broccoli photos and broccoli variety chart in the image gallery.
Fresh from the garden, broccoli has an unbeatable, sweet, gourmet flavor. "It's like eating green!" according to my young son Zane. Plus broccoli is the most nutritious of the commonly eaten vegetables, loaded with vitamin A, vitamin C, riboflavin, calcium, potassium, iron and fiber.
Although broccoli is closely related to cauliflower, brussels sprouts and cabbage, it is easier to grow and less susceptible to insect damage than any of those crops. Even the novice gardener can harvest a bountiful crop of broccoli for an extended time with a few simple tips. You can freeze any extra harvest for winter soups, quiches and casseroles.
Broccoli thrives in cool weather and grows best when daytime temperatures are between 70 and 80 degrees. Where summer temperatures rarely top 80 degrees, you can grow broccoli all summer. Here in northeast Iowa, we plant in spring and again in late summer to avoid having broccoli mature during the hottest part of the summer. In hot, southern locations, a winter crop may be your only option.
To beat the heat and get a jump on spring weeds, we start our spring crop in soil blocks or individual plant cells around March 7, a little more than five weeks before the last hard frost here in our valley (USDA Zone 4). In coastal regions of the Southeast and Southwest, where winters are mild and summers are hot, growers start transplants in early January for transplanting in mid-February. Organic farmer Andres Mejides of Elfin Acres in southern Florida starts his broccoli transplants around September 1 for a winter crop that matures in the coolest part of their season. Whether you plant your seeds indoors or out, cover the seeds with 1/4 inch of soil or finished compost, and keep the soil moist for the best germination.
In general hybrid varieties provide the best production of central heads and better performance in hot weather. But the plants of a single hybrid variety tend to mature over a short period of time. To keep the broccoli coming, plant more than one variety at a time. For spring crops we plant 'Signal' for early harvest, along with 'Arcadia,' which matures about 13 days later.
Fast-growing, vigorous plants produce the best crops, and dodge or outgrow many of the pest problems that can plague broccoli. Prepare the soil well, adding about 5 gallons of finished compost for every 100 square feet.
Space transplants or thin seedlings 10 to 24 inches between plants in 30-inch rows. In beds set plants 18 to 24 inches apart in every direction. Use dose spacing for early, small varieties, and wider spacing for later, larger varieties. Widely spaced plants tend to produce more side shoots for an extended harvest. Set the transplants just slightly deeper than they were originally growing to encourage upright growth and a sturdy stem.
Broccoli likes plenty of water, but not wet feet. If you get less than 1 inch of rain each week, irrigate deeply to make up the difference. Mulching with straw helps retain moisture and keep the soil cool. Mulch and irrigation both help to counteract the effects of hot weather, which can cause early bolting and misshapen head development, and even cause the head to rot.
Our first broccoli harvests come in late June, a good time to sow more seed for a fall crop. Final planting of a cold-hardy, long-season variety like 'Marathon' in early July (or about 90 days before your first hard fall frost) ensures an extended fall harvest. Our children love to run down the rows looking for the first broccoli heads. About seven days after they find the first silver dollar-size button, the main head will be ready to harvest.
The nubs on the broccoli actually tightly clustered flower buds. Harvest the head after the flower buds begin to swell, but before they actually open. Once you have begun to harvest a given variety, keep picking every three or four days to avoid letting any heads go past. Commercial growers cut low on the stem to get the maximum weight on each head, but they typically harvest just once. To encourage the growth of side shoots, harvest 6 inches or less of stem with the large central head, cutting with a sharp knife at a 45 degree angle.
Shortly after harvesting the central head, the side shoots will begin to develop, eventually resulting in a multiple harvest of 1- to 2-inch heads. To promote the best side shoot production, side dress with fertilizer just as the central head is beginning to form and provide consistent, deep watering.
Cut the regrowth close to the main stem to encourage the continued production of larger, tastier shoots. Harvest regularly for maximum yields and be certain to keep the shoots from flowering. Once a broccoli plant succeeds in producing flowers, it puts all of its energy into seed production and stops growing delicious things to eat. As long as you keep on cutting, you'll be amazed at how productive your plants will be.
In the Kitchen: How to Prepare Broccoli
Because broccoli is actually an immature flower, it is tender and cooks quickly. When people say they dislike broccoli. its usually because the broccoli they tried was past its peak of freshness or overcooked—both bring out unpleasant-tasting sulfurous compounds. If there is a chance cabbageworms have invaded the heads, soak them in strong salt water for 15 minutes.
The most basic preparation for broccoli is to separate the head into florets—the small flower clusters—and steam for eight to 10 minutes, until just cooked through. The color should be an even brighter green than you started out with, not gray and dingy. Open the lid just slightly to let the sulfur compounds escape.
Don't overlook the stems when you are cooking with broccoli. Stripped of their tough skins with a vegetable peeler or paring knife, broccoli stems make a delicious, slightly crunchy addition to any broccoli dish. Add them to soups or stir-fry, either as matchsticks or sliced into rounds.
We serve broccoli stems and florets steamed and tossed with a vinaigrette salad dressing just as you would a salad. Our favorite vinaigrette uses one part rice vinegar, two pasts toasted sesame oil, a little garlic and a pinch of salt, shaken well. With a seared chicken breast and a loaf of good bread, this can be a quick and delicious supper, on the table in half an hour.
Broccoli goes quite well with spicy and salty flavors, so we often add ingredients like hot pepper flakes, chopped raw garlic or Parmesan cheese to steamed or sauteed broccoli. With parsley, dill or oregano, broccoli makes an excellent ingredient in a fresh garden egg scramble.
For a new twist on broccoli, finely chop the broccoli stalks and florets. Steam lightly until almost tender, and season with olive oil, lemon juice, and salt and pepper. Prepared this way, broccoli takes on a completely new flavor and texture. Preserve any excess broccoli by splitting it lengthwise into pieces no more than 1 1/2 inches across. Blanch in boiling water for two to four minutes or steam for three to five minutes, depending on the size. Pack into containers and freeze at once.
Best Broccoli Varieties to Grow in Your Garden
Note: Days to maturity are from transplant; add 20 days for direct-seeded crops. Numbers at end of each listing indicate which source offers the variety.
'Packman' (50 days) An early season standard with nice heads, 'Packman' has a tendency to form heads prematurely in extra-early plantings. (2)
'Signal' (50 days) Early maturity and good bolt-resistance make this an excellent choice for spring crops. (1, only in commercial catalog)
'Marathon' (68 days) A wonderful fall variety, 'Marathon' has a wide maturity period and excellent frost-hardiness. (1)
'Premium Crop' (62 days) Widely adapted variety with good heat resistance, this variety produces compact heads. Excellent as a fall crop. (3)
'Early Dividend' (50 days) This early variety produces plenty of side shoots after the main head is harvested. (2)
'De Cicco (49 days) An open pollinated heirloom broccoli with small central heads, 'De Cicco' matures over a long period of time and produces a bountiful supply of side shoots. (1, 3)
'Arcadia' (63 days) Producing a big head and plenty of side shoots, Arcadia' is an excellent choice to plant with early 'Signal' or 'Packman.' (1)
'Minaret' (102 days) This romanesco type takes longer to mature than most broccoli. Seed in mid-May and give these plants plenty of room to mature by midSeptember in cold winter areas. (2, 4)
1. JOHNNY'S SELECTED SEEDS
2. TERRITORIAL SEED COMPANY
3. SOUTHERN EXPOSURE SEED EXCHANGE
4. THE COOK'S GARDEN
Broccoli is part of a highly variable plant family and is available in many permutations, in addition to the common green heading type.
The chartreuse, spiraled clusters of romanesco broccoli look more like a magical medieval structure than a vegetable. The nutty, textured heads are nice steamed or served raw, and may be listed as both broccoli and cauliflower in seed catalogs. Less heat tolerant than standard broccoli varieties, romanesco broccoli is best suited to long, cool growing seasons.
Combining the flavors of mustard greens and broccoli, this zesty cooking green is topped with small, broccoli-like florets. Direct sow in the early spring or late summer, and harvest after just 35 to 40 days, when yellow flowers have just begun to show. The leaves, stems and florets are all used together.
Sprouting or Asparagus Broccoli
Rather than producing one main head, sprouting broccoli develops a number of smaller sprouts and stems, and produces over a longer period of time than regular broccoli. Commonly overwintered in mild regions, this type is somewhat hardier than standard broccoli.
Many of the purple "broccoli" on the market are actually more closely related to cauliflower than broccoli, but they are typically less fickle and don't require the blanching necessary for fine cauliflower. The purple heads are beautiful when used raw, but universally turn green or blue when cooked.
Chris Blanchard farms eight organic acres near Highlandville, Iowa. He has a bachelor's degree in vegetable and fruit production from the University of Wisconsin.