SuNutri
SuNutri
Broccoli
Intermediate

Broccoli

Brassica oleracea var. italica

Family: Brassicaceae

Broccoli is a cool-season vegetable prized for its nutritious, tender florets. After harvesting the main head, many varieties continue producing smaller side shoots for weeks. A superfood packed with nutrients, broccoli is worth the effort to grow well.

Days to Harvest

50-100 days

Sun Needs

Full Sun (6+ hours)

Water Needs

high

Germination Temp

70°F optimal

Seed Starting

Start Indoors

6 weeks before last frost

Germination

4-10 days

Seed Depth

1/4 to 1/2 inch

Light to Germinate

No

đź’ˇ Tip: For fall crop, start seeds indoors in summer and transplant out when weather cools. Harden off transplants thoroughly.

Growing Conditions

Soil Type

Rich, well-draining soil with plenty of organic matter

pH Range

6 - 7

Spacing

18-24 inches between plants, 24-36 inches between rows

Companion Plants
âś“ Onionsâś“ Celeryâś“ Potatoesâś“ Beetsâś“ Chamomileâś“ Dill

⚠️ Avoid planting near:

âś— Tomatoesâś— Peppersâś— Strawberriesâś— Pole beans
History & Nutrition

History

Broccoli is an Italian masterpiece of agricultural selection, developed from wild cabbage (Brassica oleracea) along the Mediterranean coast over 2,000 years ago. The name derives from the Italian "broccolo," meaning "the flowering crest of a cabbage," and the Romans prized it as a delicacy—Pliny the Elder wrote about broccoli in the first century CE, and it was reportedly a favorite of the Roman emperor Tiberius's son Drusus. Italian gardeners, particularly in Calabria and Sicily, refined broccoli over centuries, selecting for larger, tighter flower heads that could be eaten before flowering. Catherine de Medici introduced broccoli to France when she married King Henry II in the 16th century, but it remained primarily an Italian vegetable for centuries. Italian immigrants brought broccoli to America in the 1880s, where it grew in Italian-American communities in California and New York. Commercial production began in the 1920s, but broccoli remained obscure to most Americans until the D'Arrigo Brothers marketing campaign of the 1920s-30s promoted "Italian sprouting broccoli" to mainstream consumers. President George H.W. Bush famously declared his dislike of broccoli in 1990, causing California growers to dump truckloads on the White House lawn in protest. Today, broccoli is one of America's most consumed vegetables, with California producing over 90% of the U.S. supply. The discovery of sulforaphane—a powerful cancer-fighting compound—in broccoli during the 1990s transformed its image from ordinary vegetable to certified "superfood."

Nutritional Benefits

  • âś“Extremely high in Vitamin C
  • âś“Excellent source of Vitamin K
  • âś“High in fiber
Climate & Temperature

Optimal Growing Temp

60°F - 70°F

Broccoli thrives in cool weather between 60-70°F. Growth slows below 50°F and above 75°F. Can tolerate light frosts. Heads form best when temperatures are consistently between 60-65°F.

Survival Range

40°F - 85°F

Can survive these temperatures

hardy
cool Season

Frost Note: Broccoli is frost-hardy and can survive temperatures down to 20°F once established. Light frosts actually improve flavor by converting starches to sugars. Mature plants handle frost better than young transplants.

Best USDA Zones

Zone 3Zone 4Zone 5Zone 6Zone 7Zone 8Zone 9

Humidity

50-70%

Moderate humidity is ideal. High humidity increases disease risk, especially black rot and downy mildew. In humid climates, ensure excellent air circulation and avoid overhead watering.

Plant Size & Growth

Height

24-36 inches

Spread

18-24 inches

Growth Habit

upright

biennialRoot Depth: Broccoli develops a moderately deep taproot reaching 18-24 inches, with most feeder roots in the top 12 inches. Deep watering encourages deeper root development.
Growth Stages

Germination

4-10 days

Seeds germinate at 45-85°F, with optimal temperature of 70°F. First cotyledon leaves emerge and unfold within a week under ideal conditions.

Seedling Stage

Duration: 4-6 weeks

True leaves: First true leaves appear 7-10 days after sprouting, showing the characteristic lobed broccoli leaf shape

Transplant ready: Ready to transplant when 4-6 inches tall with 4-5 true leaves. Harden off for 7-10 days before transplanting outdoors.

Vegetative Growth

Duration: 4-6 weeks after transplant

Rapid leaf and stem development. Plants establish strong root systems and build the large leaf canopy needed to support head formation. This is the most critical growth phase.

Flowering

Timing: 6-10 weeks after transplant depending on variety

Duration: Head forms over 7-14 days

The edible head is actually an immature flower cluster. If left unharvested, the tight florets open into yellow flowers that attract pollinators.

Harvest Maturity

Timing: 50-100 days from transplant depending on variety

  • Central head is firm and tight with tightly closed buds
  • Head reaches 4-7 inches in diameter
  • Individual florets are still tightly closed
  • Head is deep green (or appropriate variety color)
  • No yellowing or loosening of florets
Expected Yield

Per Plant

1-2 lbs from main head, plus 0.5-1 lb from side shoots

Per Square Foot

1-1.5 lbs per square foot

Harvest Frequency

One main head per plant, then side shoots every few days for 2-4 weeks

Factors Affecting Yield

  • •Cool temperatures during head formation produce tighter, larger heads
  • •Consistent moisture prevents premature flowering and loose heads
  • •Adequate nitrogen during vegetative growth supports large head development
  • •Variety selection - some produce more prolific side shoots
  • •Pest pressure - cabbage worms can destroy heads if not controlled
  • •Timing - fall crops often outperform spring crops due to better temperatures
Watering Guide

Seedling Stage

Keep consistently moist but not waterlogged - water daily in warm weather

Established Plants

1-2 inches per week, deep watering every 3-4 days

During Fruiting

Critical to maintain even moisture during head formation - never let plants wilt

Preferred Method

Drip irrigation or soaker hoses work best. Water at soil level to keep foliage dry. Deep, infrequent watering is better than frequent shallow watering.

⚠️ Critical Watering Periods

  • • Head formation
  • • Hot weather

Pro Tips

  • Mulch heavily (3-4 inches) to retain consistent soil moisture
  • Water early morning to reduce disease risk
  • Never let plants completely dry out - stress triggers bolting
  • Drought stress during head formation causes small, bitter, loose heads
Fertilizing Guide
heavy feederRecommended: High nitrogen (10-5-5) during vegetative growth, balanced (10-10-10) during head formation

Feeding Schedule

At Transplanting

Balanced fertilizer with added compost

Once at planting

Vegetative Growth

High nitrogen (10-5-5 or blood meal)

Every 2-3 weeks

Head Formation

Balanced fertilizer (10-10-10)

Every 3 weeks

Side Shoot Production

Liquid fish emulsion

Every 2 weeks

Organic Options

CompostWell-rotted manureFish emulsionBlood mealAlfalfa mealWorm castings

Side-dress with compost or aged manure every 3-4 weeks. Apply fish emulsion or blood meal for quick nitrogen boost. Add bone meal at planting for phosphorus.

Container Growing
âś“ Suitable for containers

Minimum Size

5 gallon minimum

Recommended Size

10-15 gallon for full-sized varieties

Depth Required

At least 12 inches deep, 18 inches preferred

Best Varieties for Containers

Di CiccoPackmanGreen Comet

Container Tips

  • Choose compact varieties like Di Cicco for container growing
  • Use premium potting mix with added compost for fertility
  • Containers dry out quickly - check moisture daily in hot weather
  • Feed every 2 weeks with balanced liquid fertilizer
  • Position where plants receive morning sun but afternoon shade in warm climates
  • Heavy heads may require staking for support
Succession Planting

Plant Every

2-3 weeks

Sowings/Season

2-3 plantings for extended harvest

Duration

For spring: start 6-8 weeks before last frost. For fall: start in mid to late summer

Tips

  • Succession plant for continuous harvest of main heads
  • Stagger plantings by 2-3 weeks for extended season
  • Fall crops are easier and produce better quality than spring crops in most regions
  • In mild climates, plant late summer through fall for winter harvest
Frequently Asked Questions

Related Plants