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When to Plant Brussels Sprouts in Berrien County, MI

Berrien County, Michigan Zone 6b May

May in Berrien County, Michigan — your action list

May is a pivotal month for Berrien County, Michigan gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 29
Avg. first frost October 17
Soil temp (4") 63°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
Coming up in June — start thinking about
  • Starting indoors: brussels sprouts

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Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.

Berrien County, Michigan is in USDA Zone 6b. The average last spring frost is April 29 and the first fall frost is October 17, giving you a growing season of approximately 171 days.

At an elevation of 733 feet, Berrien County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Brussels Sprouts during the growing season.

Berrien County, MI (Zone 6b) Moderate season
171 days
Last Spring Frost April 29
171 growing days
First Fall Frost October 17
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Berrien County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jul 26 – Sep 20
Recommended (50%) ✓ Fits season (24 days to spare)
Start indoors: Mar 25 Transplant: Apr 29 🍅 Harvest: Jul 29 – Sep 23
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Aug 18 – Oct 13

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Berrien County

How your county's soil matches Brussels Sprouts's growing requirements.

Soil pH

Your soil pH (6.2–7.2) is within Brussels Sprouts's preferred range (6.0–7.5).

Soil Texture

The silt loam soil in Berrien County is excellent for Brussels Sprouts — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.2%) — Brussels Sprouts will thrive.

How to Plant Brussels Sprouts

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 141 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Brussels Sprouts

Brussels Sprouts needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Brussels Sprouts Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 3.9" 3.5" 0.4" 💧 Light watering
May 3.9" 3.9" 0" ✅ Rainfall sufficient
Jun 3.9" 4.6" 0" ✅ Rainfall sufficient
Jul 3.9" 3.6" 0.3" 💧 Light watering
Aug 3.9" 3.8" 0.1" 💧 Light watering
Sep 3.9" 2.7" 1.2" 💧 Light watering
Oct 3.9" 2.2" 1.7" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Berrien County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Brussels Sprouts Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Brussels Sprouts needs ~1,842 GDD — county provides 2,864 GDD Excellent fit

Brussels Sprouts Planting Timeline — Berrien County, MI

Brussels Sprouts Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors April 29 Apr 29 – May 13
Direct Sow April 15 Apr 15 – May 6
Harvest July 29 Jul 29 – Sep 23
Fall Sowing August 8 Aug 8 – Aug 22

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Fall Sowing Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Only during dry spells

📅 Days to Maturity

90–130 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

171 days in Berrien County

Growing Tips for Brussels Sprouts in Berrien County

Direct sow Brussels Sprouts outdoors after April 29 in Berrien County when soil has warmed and frost danger has passed.

Common pests for Brussels Sprouts in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Brussels Sprouts in Berrien County, MI?

Berrien County is in Zone 6b with an average last frost of April 29. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.

What planting zone is Berrien County, MI?

Berrien County, Michigan is in USDA Hardiness Zone 6b. The average last spring frost is April 29 and first fall frost is October 17.

🌱

Your Berrien County Garden Planner — Free

A 24-page printable planner built for Berrien County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Berrien County, MI. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.