SuNutri
SuNutri
Brussels Sprouts
Intermediate

Brussels Sprouts

Brassica oleracea var. gemmifera

Family: Brassicaceae

Brussels sprouts are mini cabbages that grow along a tall stalk. They require a long, cool growing season but reward patience with sweet, nutty sprouts that taste best after frost. Once maligned, properly grown Brussels sprouts have become a culinary star.

Days to Harvest

80-130 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

1/2 inch

Light to Germinate

No

đź’ˇ Tip: Start indoors in late spring for fall harvest. Count backwards from first fall frost to determine start date.

Growing Conditions

Soil Type

Rich, well-draining soil with organic matter

pH Range

6 - 7.5

Spacing

24-30 inches between plants, 30-36 inches between rows

Companion Plants
âś“ Beetsâś“ Onionsâś“ Thymeâś“ Sageâś“ Celery

⚠️ Avoid planting near:

âś— Strawberriesâś— Tomatoesâś— Pole beans
History & Nutrition

History

Brussels sprouts emerged in Belgium sometime during the 13th to 16th centuries, with the first written references appearing in 1587 from the southern Netherlands region. The city of Brussels, which gave the vegetable its name, is located in this region where the cool, damp climate proved ideal for cultivation. From Belgium, Brussels sprouts spread across northern Europe—to France, the Netherlands, Germany, and eventually Britain, where they became a Christmas dinner tradition by the Victorian era. The vegetable reached America in the 18th century but remained unpopular until very recently, largely due to the common practice of boiling them into sulfurous mush. The rehabilitation of Brussels sprouts began in the early 2000s when restaurant chefs discovered that high-heat roasting and pan-frying caramelizes their natural sugars, transforming them from dreaded childhood punishment into craveable side dish. Food scientists also contributed by breeding varieties with lower glucosinolates—the compounds responsible for bitter flavors and pungent cooking odors. A 2011 Dutch study confirmed what growers suspected: modern varieties bred since the 1990s are genuinely milder than their predecessors. The vegetable's other secret is frost—cold temperatures convert starches to sugars, making post-frost sprouts noticeably sweeter. This is why commercial production concentrates in cool coastal regions like California's Central Coast and the Brussels area itself. Once among the most hated vegetables in America, Brussels sprouts have become a menu darling, appearing in everything from hip gastropubs to fine dining establishments, typically roasted with bacon, balsamic, or other bold accompaniments.

Nutritional Benefits

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

Optimal Growing Temp

60°F - 65°F

Brussels sprouts require a long, cool growing season with temperatures between 60-65°F for sprout formation. Plants tolerate heat during vegetative growth but need cool weather (below 70°F) when sprouts are developing. Frost actually improves flavor by converting starches to sugars.

Survival Range

20°F - 75°F

Can survive these temperatures

hardy
cool Season

Frost Note: Brussels sprouts are extremely cold-hardy, tolerating temperatures down to 20°F once established. Light frosts dramatically improve sweetness—harvest after several frosts for best flavor. Mature plants can survive hard freezes, making them an excellent late-season crop.

Best USDA Zones

Zone 3Zone 4Zone 5Zone 6Zone 7

Humidity

50-70%

Moderate humidity is ideal. High humidity increases risk of fungal diseases and aphid infestations between the tight sprouts. Good air circulation around plants is important.

Plant Size & Growth

Height

24-36 inches

Spread

18-24 inches

Growth Habit

upright

biennialRoot Depth: Brussels sprouts develop a moderate root system with most roots in the top 18 inches. Tall stalks heavy with sprouts may need staking in windy locations or loose soil.
Growth Stages

Germination

4-10 days

Seeds germinate readily at 45-85°F, with optimal germination at 70°F. Cotyledons emerge first, followed by true leaves showing characteristic brassica shape.

Seedling Stage

Duration: 4-6 weeks

True leaves: First true leaves appear 7-10 days after sprouting with the typical lobed brassica 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: 8-12 weeks after transplant

Long vegetative phase building the tall central stalk and large leaf canopy. Plants grow steadily, producing leaves that will later shelter developing sprouts in their axils.

Flowering

Timing: Sprouts form in leaf axils, not true flowers until second year

Duration: Sprout formation occurs over 6-10 weeks as temperatures cool

The edible sprouts are vegetative buds, not flowers. Plants bolt and flower in the second year if overwintered.

Harvest Maturity

Timing: 80-130 days from transplant depending on variety

  • Sprouts are 1-2 inches in diameter
  • Sprouts are firm and tight when squeezed
  • Lower sprouts mature first, harvest from bottom up
  • Best flavor develops after exposure to frost
  • Outer leaves begin yellowing on mature plants
Expected Yield

Per Plant

1-2 lbs of sprouts per plant (50-100 sprouts)

Per Square Foot

0.5-1 lb per square foot

Harvest Frequency

Harvest gradually from bottom to top over 6-8 weeks, or harvest entire stalk at once

Factors Affecting Yield

  • •Cool temperatures during sprout formation are critical for tight, sweet sprouts
  • •Frost exposure converts starches to sugars, dramatically improving flavor
  • •Consistent moisture prevents loose, bitter sprouts
  • •Adequate nitrogen during vegetative growth supports robust stalk development
  • •Topping (removing growing tip) in early fall encourages uniform sprout sizing
  • •Variety selection affects both timing and sprout size
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

Maintain consistent moisture during sprout formation—stress causes loose sprouts

Preferred Method

Drip irrigation or soaker hoses work best. Water at soil level to avoid wetting foliage. Deep, infrequent watering encourages deep root growth.

⚠️ Critical Watering Periods

  • • Sprout formation
  • • Hot weather during vegetative growth

Pro Tips

  • Mulch heavily (3-4 inches) to retain consistent soil moisture
  • Water stress during sprout formation causes loose, bitter sprouts
  • Morning watering reduces disease risk
  • Deep watering encourages deeper, more stable roots
Fertilizing Guide
heavy feederRecommended: High nitrogen (10-5-5) during vegetative growth, balanced (10-10-10) during sprout formation

Feeding Schedule

At Transplanting

Balanced fertilizer with added compost

Once at planting

Early Vegetative Growth

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

Every 2-3 weeks

Mid-Season

Balanced fertilizer (10-10-10)

Every 3-4 weeks

Sprout Formation

Balanced with extra calcium

Every 3 weeks

Organic Options

CompostWell-rotted manureFish emulsionBlood mealAlfalfa mealBone meal

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

Container Growing
âś“ Suitable for containers

Minimum Size

7 gallon minimum

Recommended Size

15-20 gallon for full-sized plants

Depth Required

At least 18 inches deep for stability—tall plants get top-heavy

Best Varieties for Containers

Jade Cross (compact)Churchill (early)Franklin (compact)

Container Tips

  • Container growing is challenging due to Brussels sprouts' long season and height
  • Use premium potting mix with added compost for fertility
  • Stake plants early as they become top-heavy with sprouts
  • Feed every 2-3 weeks with balanced liquid fertilizer
  • Position where plants receive full sun but with protection from drying winds
  • Water deeply and consistently—containers dry out faster than garden beds
✂️
Pruning Guide
Pruning Optional

Why Prune

Removing yellowed leavesTopping to encourage uniform sprout sizeImproving air circulation

When

Remove lower leaves as they yellow throughout the season. Top plants 3-4 weeks before desired harvest.

How Often

Remove yellowed leaves as needed. Topping is done once per season.

Technique

Topping: remove the growing point (top 1-2 inches of the main stem) in early fall. This stops upward growth and redirects energy into sizing up existing sprouts.

Remove

  • âś— Yellowed or diseased lower leaves
  • âś— Growing tip when topping
  • âś— Any damaged leaves

Keep

  • âś“ Healthy green upper leaves—they photosynthesize to feed sprout development
  • âś“ All developing sprouts
  • âś“ Enough leaves for plant health
Frequently Asked Questions

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