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When to Plant Turnip in Forest County, WI

Turnips are a fast-growing cool-season root vegetable with edible roots and greens. Baby turnips are sweet and tender while mature ones are more pungent.

Forest County, Wisconsin is in USDA Zone 4a. 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 83ยฐF, so choose short-season varieties of Turnip to ensure they mature before fall.

Forest County, WI (Zone 4a) Short season
133 days
Last Spring Frost May 20
133 growing days
First Fall Frost September 30

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 (53 days to spare)
Transplant: May 15 🍅 Harvest: Jun 26 – Jul 31
Recommended (50%) ✓ Fits season (56 days to spare)
Transplant: May 20 🍅 Harvest: Jul 1 – Aug 5
Safe Start (90%) ✓ Fits season (54 days to spare)
Transplant: May 31 🍅 Harvest: Jul 12 – Aug 16

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Turnip needs ~612 GDD — county provides 1,629 GDD Excellent fit

Turnip Planting Timeline โ€” Forest County, WI

Turnip Planting Calendar

Activity When Date Range
Direct Sow May 13 May 13 โ€“ Jun 3
Fall Sowing July 8 Jul 8 โ€“ Jul 22
Harvest June 24 Jun 24 โ€“ Jul 29

Plant 0.5" deep ยท 4" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

133 days

Growing Tips for Forest County

Direct sow in early spring or late summer. Harvest when roots are 2-3 inches in diameter for best flavor. Both the roots and the greens are nutritious and edible.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Turnip in Forest County, WI?

Forest County is in Zone 4a with an average last frost of May 20. Plan your Turnip planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Forest County, WI?

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

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Forest County, WI. Local conditions may vary. Last updated: April 2026.