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When to plant Celery in Clay County, MN

The best window to plant Celery in Clay County, is May 4–May 25, when soil warms to 50°F. Last frost typically hits May 11; first frost September 30. A second sowing from July 8 to July 22 extends the harvest into fall.

When to Plant Celery in Clay County, MN

Celery
Clay County, Minnesota Zone 4a June

June in Clay County, Minnesota — your action list

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

Avg. last frost May 11
Avg. first frost September 30
Soil temp (4") 59°F
Watering Low
Pest pressure Moderate
Daylight 15.7 hrs
  1. Indoor seed-starting week for celery

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

Before July arrives, get these ready
  • Fall sowing: celery

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Celery is a marshland plant that requires consistent moisture and cool temperatures to produce crisp, flavorful stalks. It is a rewarding but demanding garden crop.

Clay County, Minnesota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is September 30, giving you a growing season of approximately 142 days.

At an elevation of 1,220 feet, Clay County receives approximately 35.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Celery to ensure they mature before fall.

Clay County, MN (Zone 4a) Short season
142 days
Last Spring Frost May 11
142 growing days
First Fall Frost September 30

Clay County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.9

Drainage

Well Drained

Celery Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Start indoors: Mar 21 Transplant: May 2 🍅 Harvest: Jul 25 – Sep 19
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Aug 3 – Sep 28
Safe Start (90%) ✓ Fits season (4 days to spare)
Start indoors: Apr 11 Transplant: May 23 🍅 Harvest: Aug 15 – Oct 10

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 Clay County

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

Soil pH

Your soil pH (5.9–6.9) overlaps with Celery's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — Celery will thrive.

How to Plant Celery

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

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

Celery Water Budget

Plant needs
1.3″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 388 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Celery

Celery needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Celery Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.9" 0" ❄️ Dormant
May 5.6" 3.8" 1.8" 💧 Light watering
Jun 5.6" 3.8" 1.8" 💧 Light watering
Jul 5.6" 4.3" 1.3" 💧 Light watering
Aug 5.6" 4.2" 1.4" 💧 Light watering
Sep 5.6" 2.8" 2.8" 🚿 Regular watering
Oct 2.6" 0" ❄️ Dormant
Nov 2.2" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Celery 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.

Celery needs ~1,000 GDD — county provides 1,420 GDD Excellent fit

Celery Planting Timeline — Clay County, MN

Celery Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 4 May 4 – May 25
Harvest August 3 Aug 3 – Sep 28
Fall Sowing July 8 Jul 8 – Jul 22

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
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

1.3"/week · 1-2 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

142 days in Clay County

Growing Tips for Celery in Clay County

Direct sow Celery outdoors after May 11 in Clay County when soil has warmed and frost danger has passed.

Common pests for Celery 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. Keep soil consistently moist and never let it dry out. Blanch stalks by mounding soil or using collars for milder 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 Celery in Clay County, MN?

Clay County is in Zone 4a with an average last frost of May 11. Plan your Celery planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clay County, MN?

Clay County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is September 30.

When should I plant Celery in Clay County, MN?

In Clay County, MN, plant Celery after the last frost (around May 11) and before the first frost (around September 30). Best results when soil holds above 50°F.

What growing zone is Clay County, MN for Celery?

Clay County sits in USDA Zone 4a. Celery grows reliably in zones 2a through 10b, so it's a good fit here.

Can Celery grow in Clay County's climate?

Yes — Celery grows well in Clay County's temperate climate. Clay County averages a 142-day frost-free season, with last frost around May 11 and first frost around September 30.

🌱

Your Clay County Garden Planner — Free

A 22-page printable planner built for Clay County (Zone 4a). 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 Clay County, MN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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