Broccoli Plant: How to Grow Broccoli and When to Harvest It

Set broccoli transplants out 2 to 4 weeks before your last spring frost, from seed sown about 3 to 8 weeks earlier, and plant again in summer for a fall crop. Space plants 8 to 24 inches apart; cut the main head while compact, before its buds open.

Broccoli is a cool-season vegetable in the cabbage family, Brassicaceae, and the part you eat is a compact cluster of unopened flower buds with its attached stem. Cut it, and smaller heads sprout where the lower leaves meet the stalk; leave it, and the buds open into yellow flowers. Planting dates for four weather stations are below. Rotation and clubroot, which the whole family shares, are in our brassicas guide.

Broccoli at a glance

Sun	Full sun: at least 6 hours of direct light a day, 8 to 10 preferred
Seed depth	1/4 to 1/2 inch
Spacing	8 to 24 inches in the row, rows 18 to 36 inches apart
Days to harvest	50 to 90 from transplanting, by variety; longer for a fall crop
Temperature	Averages of 60 to 75 F preferred
Frost tolerance	No serious damage down to 28 F
Soil pH	5.8 to 7.5; every range given includes 6 to 6.5
Water	About 1 to 2 inches a week
Harvest	Main head 3 to 12 inches across by variety and season, buds still tightly closed

When to plant broccoli: spring and fall crops

Plant broccoli twice: early in spring, so heads finish before summer heat, and again in summer, so they form in the cool of fall. Most parts of the country can grow both crops in one year.

Spring. Set transplants out, or sow seed in place, 2 to 3 weeks ahead of your last frost date; one guide goes earlier, setting out 5 to 7 week old plants four weeks before it. At Minneapolis-St. Paul the state's own calendar runs later: it starts spring seed indoors in early to mid-April, weeks after the table's dates for that station. In South Carolina, transplanting runs from March 20 to April 30 in the Piedmont and from March 1 to April 10 in the Coastal Plain.

Fall. One way to time fall transplants is to work backward from the first fall frost: the variety's days to harvest from transplanting, plus about 10. Another plants early varieties 50 to 75 days ahead of the harvest it wants, a harvest that can fall several weeks past the first fall frost. By the calendar, the same Minneapolis-St. Paul state calendar sows the fall crop through July, indoors or out; a Mid-Atlantic guide sows in place in mid-July or has transplants out by the first week of August; in South Carolina, transplanting runs from August 15 to September 15 in the Piedmont and September 1 to 30 on the coast.

Broccoli planting dates at four weather stations

Station (1991-2020 normals)	Median last spring 32 F	Sow indoors, 8 to 10 weeks before (our sum)	Set out, 2 to 3 weeks before (one count; another says 4)	Median first fall 32 F	Start fall seed, 15 to 16 weeks before (our arithmetic)	Fall set-out, 60-day variety (60 days plus about 10)
Minneapolis-St. Paul, MN	Apr 23	Feb 12 to Feb 26	Apr 2 to Apr 9	Oct 18	Jun 28 to Jul 5	Aug 9
Chicago O'Hare, IL	Apr 16	Feb 5 to Feb 19	Mar 26 to Apr 2	Oct 28	Jul 8 to Jul 15	Aug 19
Washington Reagan, VA	Mar 24	Jan 13 to Jan 27	Mar 3 to Mar 10	Nov 18	Jul 29 to Aug 5	Sep 9
Atlanta Hartsfield, GA	Mar 15	Jan 4 to Jan 18	Feb 22 to Mar 1	Nov 20	Jul 31 to Aug 7	Sep 11

The two frost columns are 1991-2020 medians, and neither is a planting date: a spring 32 F night after the date shown, or a fall one before it, happens one year in two. The planting columns are our arithmetic on one count: 6 to 7 weeks of growing indoors, then out 2 to 3 weeks before the frost (another guide sets out 4 weeks before). Fall set-out counts back a 60-day variety's days to harvest plus about 10; Emerald Crown and Lieutenant are listed at 60 days from transplanting. Fall seed starts 5 to 6 weeks before that, inside the about 4 to 6 weeks given for raising fall transplants.

Use the station closest to your garden's climate. Hardiness zones rest on the average coldest winter temperature, so a zone gives no frost date. For a longer variety, move both fall dates earlier by the extra days on the label. Guides part most on fall: the Mid-Atlantic guide has transplants out by the first week of August, a month or more ahead of the count's September 9 at Washington Reagan, and another of its pages sows fall seed in late July in the center of its state.

Both ends of the season can spoil a head. Days of 86 F with nights warmer than 77 F can mean no crown at all, though plants may still crown if it cools off, and high summer heat brings loose heads that taste bitter. Cold has its own risk: temperatures below 45 F may hold back heading or bring on bolting, and cole crops can bolt after 10 or more straight days at 35 to 50 F that follow good growing weather, more often the bigger the plants. In South Carolina, broccoli does better in fall, since spring temperature swings can give uneven heads with loose bud clusters.

Starting broccoli seeds indoors

Sow broccoli for transplants about 3 to 8 weeks before they are due in the garden in spring, and about 4 to 6 weeks before in fall.

1. Sow shallow. Use a sterile, soilless seedling mix and press seed down 1/4 to 1/2 inch, or put 2 seeds in each cell of a 72-cell flat; in outdoor seedbeds, sow 1/4 inch deep.
2. Decide on heat. For an early spring crop, one guide holds the soil at 75 to 80 F, if possible, until the seed sprouts, then lowers the air to about 60 F. Another skips bottom heat because seed sprouts well in regular summer temperatures, a reason that, in our reading, fits a summer sowing for fall. Seeds should come up in about two weeks.
3. Light and feed. Turn bright grow lights on as soon as seedlings appear. From the first true leaf, feed weekly with starter solution mixed at half strength, then twice a week after the second.
4. Harden them off. At four or five true leaves, which can take about four weeks, water less and ease the plants outdoors over a week, sheltered from wind at first. Spring plants need enough cold to toughen them, but keep them from freezing.

For fall, you can also sow in place, three seeds every 8 to 10 inches, thinned to one.

Setting out broccoli transplants: spacing

Set out young plants that are still growing hard, with a good root system and 4 to 6 mature leaves. Older plants risk buttoning, a small head that forms early and soon flowers: larger, older transplants are prone to it, and plants left in seed flats too long may button.

1. Plant at the right depth. Set each plant at the level it grew in its pot, or slightly deeper.
2. Water them in. Water thoroughly to start root growth and close air pockets, or use a liquid starter rich in phosphorus.
3. Cover the row. Row cover shields new plants from wind and insects: a cold-protecting fabric in spring, a lightweight one in summer to avoid overheating. Pin or bury the edges, since a cover loosened by strong wind can do more damage than none.

Buttoning follows cold or a shortage of water or nutrients around transplanting. Early flowering may also be caused by long chilling of young plants, very early planting, plants kept at a garden center until too old or dry, and severe drought.

How far apart to plant broccoli

Space broccoli plants 8 to 24 inches apart, with 18 to 36 inches between rows. In beds, one guide sets plants a foot apart each way, though another says a 1 by 1 foot grid makes smaller heads and fewer side shoots, and crowding can encourage bolting.

Broccoli numbers across six guides

	The range the guides give
Seed depth	1/4 to 1/2 in
Transplant age	About 3 to 8 weeks in spring, about 4 to 6 in fall; 4 to 6 leaves
In the row	8 to 24 in
Between rows	18 to 36 in
Days to harvest	50 to 90 from transplanting; add about 20 if sown in place

Feeding and watering broccoli

Keep broccoli growing without a pause. It is not worth growing unless the plants take up water and nutrients steadily, and plants without steady water may form small, off-flavored heads.

Water. Aim for even soil moisture: about 1 to 2 inches a week. One guide waters deeply and infrequently; another soaks the soil at least once a week when a week brings less than an inch of rain, more often in sand. Water early in the day so leaves are dry by nightfall, wetting the soil 6 inches deep or more. The two critical times are getting plants established and forming heads.

Mulch. Broccoli has shallow, fibrous roots, so hoe with care or mulch thickly: weed-free straw, or clippings untouched by herbicide, 3 to 4 inches deep. Once temperatures pass 80 F, mulch also helps cool the soil.

Feed. Test the soil first; the pH ranges given run from 5.8 to 7.5, and all include 6 to 6.5. Broccoli is a heavy feeder: side-dress 3 to 4 weeks after transplanting or thinning, or once seedlings sown in place reach 6 inches, and again with nitrogen when the head is quarter-sized. More is not better: one kind of hollow stem comes from excess nitrogen along with warm weather, overwatering and acid soil.

When to harvest broccoli heads

Cut the main head once it is firm and full-sized but its buds are still tight, before any open to show yellow. Size varies with variety and season, from 3 to 12 inches across.

• Days. Heads are ready 50 to 90 days after transplanting, by variety; add about 20 days for seed sown in place.
• The cut. Take the head with about 5 to 8 inches of stem, and leave the rest of the plant growing.
• Do not wait. Harvest promptly, since a ripe head soon loses quality, and cut at once if flowers start to open; yellow flowers and swollen buds mean a head past maturity.
• Storage. Near 32 F with relative humidity of 95 percent or higher, broccoli keeps 10 to 14 days. In a home refrigerator, keep it unwashed in a perforated bag for 3 to 5 days.

Side shoots after the main head

Most broccoli varieties can keep going after the main head is cut: smaller side heads form in the leaf axils lower down, and you can usually pick them for several weeks.

Extra water and fertilizer bring many side shoots 3 to 6 inches long; side-dress again when the central head comes off. Pick often: regular harvests encourage more. Late side shoots may be only 1 to 2 inches across.

Variety matters: some varieties, Packman among them, make many secondary heads, while close spacing holds side shoots back. Broccoli still grows after the first light frosts of fall, and its leaves are edible, used like kale or collards.

Cabbage worms and other broccoli pests

Caterpillars are the main pests of broccoli and its relatives. Three commonly attack it: imported cabbageworm, cabbage looper and diamondback moth larvae, which chew holes in the leaves; cabbageworms and loopers sometimes bore into heads.

• Imported cabbageworm. A velvety green caterpillar; the adult is a white butterfly. Damaged young plants may fail to form heads.
• Cabbage looper. Smooth and light green, it arches into a loop as it crawls; the moth is brown and most active at night.
• Diamondback moth. Small, pale green and pointed at both ends, its feeding leaves shot holes or often windowpanes where the upper skin of the leaf is left.
• Flea beetles. Tiny jumping beetles that riddle seedlings with small holes. They hit mustard and turnips hardest, since those lack the waxy leaf coating that protects broccoli.
• Aphids. Colonies on leaf undersides crinkle and curl the leaves; in South Carolina, aphids tend to show up more in fall.

Control starts with cover. Floating row cover keeps the butterflies from laying eggs; cover seedlings from planting day against flea beetles and root maggots, and anchor the edges to the soil. In small plantings, pick caterpillars by hand, scouting every few days; fine mesh netting or screens can also work, keeping moths from laying eggs. The worms are worse in fall, after months of buildup, until numbers drop near the first frost. Get pests in check before heads begin. Faster-maturing varieties take less damage.

Clear crop residue right after harvest, plant small flowers such as sweet alyssum, dill, cilantro and buckwheat to draw parasitic flies and wasps, and avoid broad-spectrum insecticides that kill those helpers. To float hidden worms out of a cut head, soak it in salty water. Diseases include Alternaria, black rot and clubroot; black rot is the most severe in South Carolina.

What to plant with broccoli

Set small plants close to larger ones, radishes at the base of broccoli for example, and plant lettuce between or within the rows of later crops such as broccoli to save space. In an Iowa study, plantings of thyme, onion and nasturtium helped reduce looper and cabbageworm damage in broccoli, and nasturtium also serves as a trap crop for brassicas. For flea beetles, arugula, mustard and napa cabbage can serve as trap crops. One guide says broccoli interferes with relatives such as cabbage and cauliflower, citing no study. See every pairing, with its evidence, in our companion planting guide.

Broccoli seeds and supplies

Choose seed for the season, though guides split on fall. For spring, pick a heat-tolerant variety with a short cycle, 50 to 60 days. For fall, one guide grows a longer variety of 60 to 85 days, so heads form in cool weather; another picks early varieties, and a third midseason and storage types. Varieties named include Packman, Green Comet and Premium Crop (listed at 50, 55 and 65 days), and Emerald Crown, Lieutenant, Belstar and the slow-bolting Green Magic. Guides group the kinds differently. One sorts broccoli into four types: heading, Romanesco, sprouting and raab, which it calls a type of turnip rather than a true broccoli; another counts raab as a broccoli and adds Chinese broccoli. For broccoli eaten as sprouts, see our sprouting seeds guide. A cell tray raises spring transplants; row cover or fine netting can keep moths and flea beetles off.

What you'll need for broccoli

As an Amazon Associate we earn from qualifying purchases.

• 

  Seed Kingdom Packman Broccoli Seeds

  Varieties named include Packman, Green Comet and Premium Crop.

  Check price on Amazon
• 

  Park Seed Belstar Broccoli Seeds

  Varieties named include Emerald Crown, Lieutenant, Belstar and the slow-bolting Green Magic.

  Check price on Amazon
• 

  Burpee 72 Cell Greenhouse Kit

  A cell tray raises spring transplants.

  Check price on Amazon

Sources we used

Each page below was saved as we read it in October 2026.

• "Utah State University Extension: How to Grow Broccoli in Your Garden" (March 2020)
• "University of Minnesota Extension: Growing broccoli in home gardens" (reviewed 2026)
• "Illinois Extension, Home Vegetable Gardening: Broccoli"
• "Clemson Cooperative Extension, HGIC 1301: Broccoli" (updated January 20, 2023) and "HGIC 2203: Cabbage, Broccoli and Other Cole Crop Insect Pests" (updated May 16, 2025)
• "University of Maryland Extension: Growing Broccoli in a Home Garden" (updated July 24, 2023), with its pages on the imported cabbageworm, cabbage looper, flea beetles and bolting
• "Johnny's Selected Seeds: Standard Heading Broccoli Key Growing Information" (a seed company)
• Companion plants: University of Minnesota Extension, University of Maryland Extension and its lettuce page, Utah State University Extension and Illinois Extension
• "NOAA NCEI: U.S. Climate Normals, 1991-2020", freeze dates for the four airport stations in the planting table
• "USDA ARS: 2023 USDA Plant Hardiness Zone Map", for what a hardiness zone measures

Related guides

• The brassicas guide: what the cabbage family shares.
• Growing cauliflower: broccoli's close relative.
• Growing kale: a leaf crop for the same fall beds.
• Turnips and rutabagas: cabbage-family roots sown for fall.
• Radishes: for the gaps around young broccoli.
• Arugula: a quick brassica green that can lure flea beetles.

Frequently asked questions

When should you plant broccoli?

Plant broccoli in spring and summer. Set spring transplants out 2 to 4 weeks before your last frost. For fall, one count works back from the first frost: the variety's days to harvest from transplanting, plus about 10. At Chicago O'Hare, our arithmetic gives March 26 to April 2 on a 2 to 3 week count, and August 19 for a 60-day variety.

When is broccoli ready to harvest?

Broccoli is ready when the main head is firm and full-sized and the buds are still tight, with no yellow flowers. Heads run 3 to 12 inches across by variety and season, 50 to 90 days from transplanting. Yellow flowers and swelling buds are signs the head is past maturity, so cut promptly.

Does broccoli grow back after cutting?

Yes, most varieties can send up smaller side shoots after the main head is cut, from the leaf axils lower on the stem, and you can usually pick them for several weeks. Extra water and fertilizer bring many shoots 3 to 6 inches long, and regular picking encourages more.

How far apart do you plant broccoli?

Give each broccoli plant 8 to 24 inches of row, with 18 to 36 inches between rows. In beds, one guide sets plants a foot apart each way, though another says that close a spacing shrinks heads.

How long does broccoli take to grow?

Broccoli takes 50 to 90 days from transplanting to harvest, by variety, and longer for a fall crop. Add the time to raise the transplant, about 3 to 8 weeks. Sown in place, it needs about 20 days more.

Why is my broccoli making tiny heads or flowering early?

Usually stress. Plants that met cold, or ran short of water or nutrients around transplanting, can button into small early heads, and bigger transplants button more. Days of 86 F with nights warmer than 77 F can leave no crown at all, though one may form if the weather cools.

How do you keep cabbage worms off broccoli?

Cover young plants with floating row cover, which keeps the white butterflies from laying eggs, and pick off any caterpillars you find, scouting small plantings every few days. The worms build up for months, so fall plantings suffer more than spring ones.

What can I plant with broccoli?

Plant small crops around it: radishes at the base of broccoli, and lettuce between or within its rows. In an Iowa study, plantings of thyme, onion and nasturtium helped reduce caterpillar damage on broccoli, and nasturtium also serves as a trap crop. One guide says, citing no study, that broccoli interferes with cabbage and cauliflower.