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When to Plant Celeriac in Cornucopia, WI

Bayfield County, Wisconsin Zone 4b July

Top priorities for Bayfield County, Wisconsin gardeners in July

We've pulled the most time-sensitive tasks for Bayfield County, Wisconsin this July and put them front and centre. Tackle them in order.

Avg. last frost May 14
Avg. first frost October 3
Soil temp (4") 70°F
Watering Low
Pest pressure Moderate
Daylight 15.3 hrs
  1. Direct-sow celeriac for cool weather

    Count back from your first frost (October 3) — these need to mature before the cold arrives.

Looking ahead to August
  • First harvests: celeriac

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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.

Cornucopia, Wisconsin is in USDA Zone 4b. The average last spring frost is May 14 and the first fall frost is October 3, giving you a growing season of approximately 142 days.

At an elevation of 619 feet, Bayfield County receives approximately 36.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Celeriac to ensure they mature before fall.

Cornucopia, WI (Zone 4b) Short season
142 days
Last Spring Frost May 14
142 growing days
First Fall Frost October 3

Cornucopia Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Celeriac Planting Risk Windows

Early Start (70% safe) ✓ Fits season (0 days to spare)
Start indoors: Mar 26 Transplant: May 7 🍅 Harvest: Aug 20 – Sep 24
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Aug 27 – Oct 1
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: Apr 20 Transplant: Jun 1 🍅 Harvest: Sep 14 – Oct 19

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 Cornucopia

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

Soil pH

Your soil pH (5.8–6.8) overlaps with Celeriac's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Celeriac

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

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

Celeriac Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Celeriac

Celeriac 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 Celeriac Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.8" 0" ❄️ Dormant
May 3.9" 4.4" 0" ✅ Rainfall sufficient
Jun 3.9" 4.7" 0" ✅ Rainfall sufficient
Jul 3.9" 4.4" 0" ✅ Rainfall sufficient
Aug 3.9" 3.4" 0.5" 💧 Light watering
Sep 3.9" 3.2" 0.7" 💧 Light watering
Oct 3.9" 3.1" 0.8" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Celeriac 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.

Celeriac needs ~1,100 GDD — county provides 1,420 GDD Good fit

Celeriac Planting Timeline — Cornucopia, WI

Celeriac Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors May 14 May 14 – May 28
Direct Sow May 7 May 7 – May 28
Harvest August 27 Aug 27 – Oct 1
Fall Sowing July 11 Jul 11 – Jul 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Natural rainfall sufficient

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4b

📆 Growing Season

142 days in Bayfield County

Growing Tips for Celeriac in Cornucopia

Direct sow Celeriac outdoors after May 14 in Bayfield County when soil has warmed and frost danger has passed.

Common pests for Celeriac in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

🌱

Your Bayfield County Garden Planner — Free

A 22-page printable planner built for Bayfield 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.

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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 Bayfield County, WI. Local conditions may vary. Last updated: July 2026.