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When to Plant Celery in Coles County, IL

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.

Coles County, Illinois is in USDA Zone 5b. The average last spring frost is April 14 and the first fall frost is October 17, giving you a growing season of approximately 186 days.

At an elevation of 779 feet, Coles County receives approximately 34.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Celery during the growing season.

Coles County, IL (Zone 5b) Moderate season
186 days
Last Spring Frost April 14
186 growing days
First Fall Frost October 17

Coles County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: Jul 2 – Aug 27
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: Jul 7 – Sep 1
Safe Start (90%) ✓ Fits season (46 days to spare)
Start indoors: Mar 24 Transplant: Apr 28 🍅 Harvest: Jul 21 – Sep 15

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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,423 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Celery needs ~1,450 GDD — county provides 2,697 GDD Excellent fit

Celery Planting Timeline โ€” Coles County, IL

Celery Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 14 Apr 14 โ€“ Apr 28
Direct Sow March 31 Mar 31 โ€“ Apr 21
Fall Sowing August 8 Aug 8 โ€“ Aug 22
Harvest July 7 Jul 7 โ€“ Sep 1

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

80โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

186 days

Growing Tips for Coles County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Celery in Coles County, IL?

Coles County is in Zone 5b with an average last frost of April 14. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Coles County, IL?

Coles County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 14 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Coles County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Coles County, IL. Local conditions may vary. Last updated: April 2026.