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When to plant Celeriac in Grant County County,

Grant County County gardeners should plant Celeriac between April 24 and May 15 in spring. With Grant County County's Zone 4b climate (last frost May 1), Celeriac needs 120 days to mature — plant by June 9 for a full harvest. A second sowing from July 15 to July 29 extends the harvest into fall.

When to Plant Celeriac in Grant County, MN

Grant County, Minnesota Zone 4b June

What to do in June

Welcome to June in Zone 4b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 1
Avg. first frost October 7
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 15.5 hrs
  1. Fire up the seed-starting tray: celeriac

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

To set up a strong July, finish these tasks
  • 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.

Grant County, Minnesota is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 1,371 feet, Grant County receives approximately 31.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Celeriac to ensure they mature before fall.

Grant County, MN (Zone 4b) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Celeriac Planting Risk Windows

Early Start (70% safe) ✓ Fits season (21 days to spare)
Start indoors: Mar 14 Transplant: Apr 25 🍅 Harvest: Aug 8 – Sep 12
Recommended (50%) ✓ Fits season (19 days to spare)
Start indoors: Mar 20 Transplant: May 1 🍅 Harvest: Aug 14 – Sep 18
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Aug 27 – Oct 1

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 Grant County

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

Soil pH

Your soil pH (6.1–6.8) is within Celeriac's preferred range (6.0–7.0).

Soil Texture

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

Drainage

Celeriac is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is moderate (4.0%). 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.

Celeriac Water Budget

Plant needs
0.9″/week
Rainfall provides
0.8″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 578 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 1.4" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 3.9" 4.1" 0" ✅ Rainfall sufficient
Jun 3.9" 4.4" 0" ✅ Rainfall sufficient
Jul 3.9" 3.7" 0.2" 💧 Light watering
Aug 3.9" 2.9" 1" 💧 Light watering
Sep 3.9" 3.2" 0.7" 💧 Light watering
Oct 3.9" 2.1" 1.8" 💧 Light watering
Nov 1.9" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Grant 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 ~1,348 GDD — county provides 1,947 GDD Excellent fit

Celeriac Planting Timeline — Grant County, MN

Celeriac Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Harvest August 14 Aug 14 – Sep 18
Fall Sowing July 15 Jul 15 – Jul 29

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · 1-2 times/week

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 4b

📆 Growing Season

159 days in Grant County

Growing Tips for Celeriac in Grant County

Direct sow Celeriac outdoors after May 01 in Grant 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 →

Frequently Asked Questions

When should I plant Celeriac in Grant County, MN?

Grant County is in Zone 4b with an average last frost of May 1. Plan your Celeriac planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, MN?

Grant County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 7.

When should I plant Celeriac in Grant County, ?

In Grant County, , plant Celeriac after the last frost (around May 1) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Grant County, for Celeriac?

Grant County sits in USDA Zone 4b. Celeriac grows reliably in zones 3a through 9b, so it's a good fit here.

Can Celeriac grow in Grant County's climate?

Yes — Celeriac grows well in Grant County's temperate climate. Grant County averages a 159-day frost-free season, with last frost around May 1 and first frost around October 7.

🌱

Your Grant County Garden Planner — Free

A 22-page printable planner built for Grant 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 Grant County, MN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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