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When to Plant Celeriac in Douglas 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.

Douglas County, Wisconsin is in USDA Zone 3b. The average last spring frost is May 16 and the first fall frost is September 28, giving you a growing season of approximately 135 days.

At an elevation of 1,147 feet, Douglas County receives approximately 31.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79ยฐF, so choose short-season varieties of Celeriac to ensure they mature before fall.

Douglas County, WI (Zone 3b) Short season
135 days
Last Spring Frost May 16
135 growing days
First Fall Frost September 28

Douglas County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (7 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Aug 23 – Sep 13
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Aug 29 – Sep 19
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Sep 12 – 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
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 629 gal / 100 sq ft
Celeriac needs ~1,018 GDD — county provides 1,248 GDD Good fit

Celeriac Planting Timeline โ€” Douglas County, WI

Celeriac Planting Calendar

Activity When Date Range
Start Indoors April 4 Apr 4 โ€“ Apr 18
Transplant Outdoors May 16 May 16 โ€“ May 30
Direct Sow May 9 May 9 โ€“ May 30
Fall Sowing July 6 Jul 6 โ€“ Jul 20
Harvest August 29 Aug 29 โ€“ Sep 19

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 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 3b

Growing Season

135 days

Growing Tips for Douglas 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 Douglas County, WI?

Douglas County is in Zone 3b with an average last frost of May 16. Plan your Celeriac planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Douglas County, WI?

Douglas County, Wisconsin is in USDA Hardiness Zone 3b. The average last spring frost is May 16 and first fall frost is September 28.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Douglas County gardeners in Zone 3b 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 Douglas County, WI. Local conditions may vary. Last updated: April 2026.