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When to Plant Celeriac in Koochiching County, MN

Koochiching County, Minnesota Zone 3b May

May in the garden — Koochiching County, Minnesota

Each item below is timed to Koochiching County, Minnesota's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 22
Avg. first frost September 18
Soil temp (4") 51°F
Watering Low
Pest pressure Low
Daylight 15 hrs
  1. Time to transplant celeriac

    Your last frost (May 22) has passed. These warm-season crops can handle outdoor soil now.

  2. Direct-sow celeriac

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

Get ahead of June
  • Fall sowing: 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.

Koochiching County, Minnesota is in USDA Zone 3b. The average last spring frost is May 22 and the first fall frost is September 18, giving you a growing season of approximately 119 days.

At an elevation of 508 feet, Koochiching County receives approximately 41.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79°F, so choose short-season varieties of Celeriac to ensure they mature before fall.

Koochiching County, MN (Zone 3b) Short season
119 days
Last Spring Frost May 22
119 growing days
First Fall Frost September 18
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Koochiching County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Aug 29 – Sep 19
Recommended (50%) ✗ May not fit
Start indoors: Apr 10 Transplant: May 22 🍅 Harvest: Sep 4 – Sep 25
Safe Start (90%) ✗ May not fit
Start indoors: May 4 Transplant: Jun 15 🍅 Harvest: Sep 28 – 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 Koochiching County

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

Soil pH

Your soil pH (5.8–7.2) overlaps with Celeriac's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Celeriac.

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.

Plant Water Budget

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

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 1.5" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 4" 0" ❄️ Dormant
May 3.9" 5" 0" ✅ Rainfall sufficient
Jun 3.9" 5" 0" ✅ Rainfall sufficient
Jul 3.9" 5" 0" ✅ Rainfall sufficient
Aug 3.9" 3.8" 0.1" 💧 Light watering
Sep 3.9" 3.7" 0.2" 💧 Light watering
Oct 2.8" 0" ❄️ Dormant
Nov 3.2" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Koochiching 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 ~1,018 GDD — county provides 1,100 GDD Good fit

Celeriac Planting Timeline — Koochiching County, MN

Celeriac Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 – Apr 24
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 15 May 15 – Jun 5
Harvest September 4 Sep 4 – Sep 25
Fall Sowing June 26 Jun 26 – Jul 10

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 Transplant Outdoors Direct Sow Fall Sowing
July Fall Sowing
August
September Harvest
October
November
December
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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 3b

📆 Growing Season

119 days in Koochiching County

Growing Tips for Celeriac in Koochiching County

Direct sow Celeriac outdoors after May 22 in Koochiching County when soil has warmed and frost danger has passed.

Your 119.0-day growing season in Koochiching County is tight for Celeriac (100.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

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 →

Frequently Asked Questions

When should I plant Celeriac in Koochiching County, MN?

Koochiching County is in Zone 3b with an average last frost of May 22. Plan your Celeriac planting based on this frost date — see the calendar above for exact timing.

What planting zone is Koochiching County, MN?

Koochiching County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 22 and first fall frost is September 18.

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Your Koochiching County Garden Planner — Free

A 24-page printable planner built for Koochiching County (Zone 3b). 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 Koochiching County, MN. 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.