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When to Plant Celeriac in Gratiot County, MI

Gratiot County, Michigan Zone 6a May

Your May planting checklist for Gratiot County, Michigan

Your Gratiot County, Michigan garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 30
Avg. first frost October 16
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
To set up a strong June, finish these tasks
  • Starting indoors: 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.

Gratiot County, Michigan is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 16, giving you a growing season of approximately 169 days.

At an elevation of 1,055 feet, Gratiot County receives approximately 38.8 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.

Gratiot County, MI (Zone 6a) Moderate season
169 days
Last Spring Frost April 30
169 growing days
First Fall Frost October 16

Gratiot County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Aug 10 – Sep 14
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Aug 13 – Sep 17
Safe Start (90%) ✓ Fits season (27 days to spare)
Start indoors: Apr 11 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.

Soil Compatibility in Gratiot County

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

Soil pH

Your soil pH (6.2–6.8) is within Celeriac's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Celeriac will thrive.

How to Plant Celeriac

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
1.0″/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 1.8" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.9" 3.9" 0" ✅ Rainfall sufficient
May 3.9" 3.9" 0" ✅ Rainfall sufficient
Jun 3.9" 5.3" 0" ✅ Rainfall sufficient
Jul 3.9" 3.7" 0.2" 💧 Light watering
Aug 3.9" 4.4" 0" ✅ Rainfall sufficient
Sep 3.9" 3.7" 0.2" 💧 Light watering
Oct 3.9" 2.8" 1.1" 💧 Light watering
Nov 3" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Gratiot 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 2,070 GDD Excellent fit

Celeriac Planting Timeline — Gratiot County, MI

Celeriac Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 16 Apr 16 – May 7
Harvest August 13 Aug 13 – Sep 17
Fall Sowing August 7 Aug 7 – Aug 21

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 6a

📆 Growing Season

169 days in Gratiot County

Growing Tips for Celeriac in Gratiot County

Direct sow Celeriac outdoors after April 30 in Gratiot 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 Gratiot County, MI?

Gratiot County is in Zone 6a with an average last frost of April 30. Plan your Celeriac planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gratiot County, MI?

Gratiot County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 16.

🌱

Your Gratiot County Garden Planner — Free

A 24-page printable planner built for Gratiot County (Zone 6a). 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 Gratiot County, MI. 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.