Blog

When to Plant Rutabaga in Forest County, WI

Forest County, Wisconsin Zone 4b May

Your May game plan for Forest County, Wisconsin

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Forest County, Wisconsin.

Avg. last frost May 20
Avg. first frost September 30
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Scatter rutabaga into prepared beds

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

Instant PDF download. No spam, unsubscribe any time.

Rutabagas are a cross between turnips and cabbage, producing large yellow-fleshed roots with a sweet, mild flavor. They are excellent mashed, roasted, or in stews.

Forest County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 20 and the first fall frost is September 30, giving you a growing season of approximately 133 days.

At an elevation of 556 feet, Forest County receives approximately 34.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Rutabaga to ensure they mature before fall.

Forest County, WI (Zone 4b) Short season
133 days
Last Spring Frost May 20
133 growing days
First Fall Frost September 30
Share this guide:

Forest County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Transplant: May 15 🍅 Harvest: Aug 7 – Sep 11
Recommended (50%) ✓ Fits season (14 days to spare)
Transplant: May 20 🍅 Harvest: Aug 12 – Sep 16
Safe Start (90%) ✓ Fits season (12 days to spare)
Transplant: May 31 🍅 Harvest: Aug 23 – Sep 27

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 Forest County

How your county's soil matches Rutabaga's growing requirements.

Soil pH

Your soil pH (5.8–6.7) overlaps with Rutabaga's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Rutabaga

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
0.7″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Rutabaga

Rutabaga needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Rutabaga Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 3" 4" 0" ✅ Rainfall sufficient
Jun 3" 4.1" 0" ✅ Rainfall sufficient
Jul 3" 3.6" 0" ✅ Rainfall sufficient
Aug 3" 4.1" 0" ✅ Rainfall sufficient
Sep 3" 3.4" 0" ✅ Rainfall sufficient
Oct 2.5" 0" ❄️ Dormant
Nov 2.4" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Rutabaga 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.

Rutabaga needs ~1,102 GDD — county provides 1,629 GDD Excellent fit

Rutabaga Planting Timeline — Forest County, WI

Rutabaga Planting Calendar

Activity When Date Range
Direct Sow May 13 May 13 – Jun 3
Harvest August 5 Aug 5 – Sep 9
Fall Sowing July 8 Jul 8 – Jul 22

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Direct Sow
June Direct Sow
July Fall Sowing
August Harvest
September Harvest
October
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

133 days in Forest County

Growing Tips for Rutabaga in Forest County

Direct sow Rutabaga outdoors after May 20 in Forest County when soil has warmed and frost danger has passed.

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

General growing tips

Direct sow in early summer for fall harvest. Thin seedlings to 6-8 inches apart. Flavor improves significantly after a few light frosts.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rutabaga in Forest County, WI?

Forest County is in Zone 4b with an average last frost of May 20. Plan your Rutabaga planting based on this frost date — see the calendar above for exact timing.

What planting zone is Forest County, WI?

Forest County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 20 and first fall frost is September 30.

🌱

Your Forest County Garden Planner — Free

A 24-page printable planner built for Forest County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Forest County, WI. 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.