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When to Plant Brussels Sprouts in Chippewa County, WI

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

Chippewa County, Wisconsin is in USDA Zone 4a. The average last spring frost is May 15 and the first fall frost is September 28, giving you a growing season of approximately 136 days.

At an elevation of 916 feet, Chippewa County receives approximately 40.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Brussels Sprouts to ensure they mature before fall.

Chippewa County, WI (Zone 4a) Short season
136 days
Last Spring Frost May 15
136 growing days
First Fall Frost September 28

Chippewa County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Aug 10 – Oct 5
Recommended (50%) ✗ May not fit
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Aug 14 – Oct 9
Safe Start (90%) ✗ May not fit
Start indoors: Apr 14 Transplant: May 26 🍅 Harvest: Aug 25 – Oct 20

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 Chippewa County

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

Soil pH

Your soil pH (5.8โ€“6.7) overlaps with Brussels Sprouts's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The silt loam soil in Chippewa County is excellent for Brussels Sprouts โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Brussels Sprouts.

Organic Matter

Organic matter is excellent (4.4%) โ€” Brussels Sprouts will thrive.

How to Plant Brussels Sprouts

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
1.3″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.8" 0" โ„๏ธ Dormant
Apr โ€” 3.6" 0" โ„๏ธ Dormant
May 3.9" 4.3" 0" โœ… Rainfall sufficient
Jun 3.9" 5.3" 0" โœ… Rainfall sufficient
Jul 3.9" 4.2" 0" โœ… Rainfall sufficient
Aug 3.9" 4.2" 0" โœ… Rainfall sufficient
Sep 3.9" 4.3" 0" โœ… Rainfall sufficient
Oct โ€” 3.4" 0" โ„๏ธ Dormant
Nov โ€” 2.5" 0" โ„๏ธ Dormant
Dec โ€” 2.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Chippewa County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,348 GDD — county provides 1,666 GDD Good fit

Brussels Sprouts Planting Timeline โ€” Chippewa County, WI

Brussels Sprouts Planting Calendar

Activity When Date Range
Start Indoors April 3 Apr 3 โ€“ Apr 17
Transplant Outdoors May 15 May 15 โ€“ May 29
Direct Sow May 8 May 8 โ€“ May 29
Harvest August 14 Aug 14 โ€“ Oct 9
Fall Sowing July 6 Jul 6 โ€“ Jul 20

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.9"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“130 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

136 days in Chippewa County

Growing Tips for Brussels Sprouts in Chippewa County

Direct sow Brussels Sprouts outdoors after May 15 in Chippewa County when soil has warmed and frost danger has passed.

Your 136.0-day growing season in Chippewa County is tight for Brussels Sprouts (90.0-130.0 days to maturity). Start indoors and choose early-maturing varieties.

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 Chippewa County, WI?

Chippewa County is in Zone 4a with an average last frost of May 15. Plan your Brussels Sprouts planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Chippewa County, WI?

Chippewa County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is May 15 and first fall frost is September 28.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Chippewa County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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