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When to Plant Celeriac in Pierce County, WI

Celeriac is a celery relative grown for its knobby, flavorful root rather than its stalks. It has a rich celery flavor and is excellent roasted, mashed, or in soups.

Pierce County, Wisconsin is in USDA Zone 4a. The average last spring frost is April 28 and the first fall frost is October 8, giving you a growing season of approximately 163 days.

At an elevation of 523 feet, Pierce County receives approximately 35.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Celeriac to ensure they mature before fall.

Pierce County, WI (Zone 4a) Moderate season
163 days
Last Spring Frost April 28
163 growing days
First Fall Frost October 8

Pierce County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Mar 8 Transplant: Apr 19 🍅 Harvest: Aug 2 – Sep 6
Recommended (50%) ✓ Fits season (23 days to spare)
Start indoors: Mar 17 Transplant: Apr 28 🍅 Harvest: Aug 11 – Sep 15
Safe Start (90%) ✓ Fits season (22 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Aug 29 – Oct 3

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
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,037 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Celeriac needs ~1,430 GDD — county provides 2,119 GDD Excellent fit

Celeriac Planting Timeline โ€” Pierce County, WI

Celeriac Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 โ€“ Mar 31
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Direct Sow April 21 Apr 21 โ€“ May 12
Fall Sowing July 16 Jul 16 โ€“ Jul 30
Harvest August 11 Aug 11 โ€“ Sep 15

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

100โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

163 days

Growing Tips for Pierce County

Start seeds indoors 10-12 weeks before last frost. Remove side roots as they develop to encourage a single large bulb. Harvest after a light frost for best flavor.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Parsnip

Level Up Your Garden

Frequently Asked Questions

When should I plant Celeriac in Pierce County, WI?

Pierce County is in Zone 4a with an average last frost of April 28. Plan your Celeriac planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pierce County, WI?

Pierce County, Wisconsin is in USDA Hardiness Zone 4a. The average last spring frost is April 28 and first fall frost is October 8.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pierce 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 Pierce County, WI. Local conditions may vary. Last updated: April 2026.