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When to plant Celery in Grundy County, IL

For Grundy County, gardeners: plant Celery April 6 through April 27 once soil reads 50°F. A second sowing from August 8 to August 22 extends the harvest into fall.

When to Plant Celery in Grundy County, IL

Celery
Grundy County, Illinois Zone 5b July

What to do in July

We've pulled the most time-sensitive tasks for Grundy County, Illinois this July and put them front and centre. Tackle them in order.

Avg. last frost April 20
Avg. first frost October 17
Soil temp (4") 77°F
Watering Moderate
Pest pressure High
Daylight 14.7 hrs
  1. Basket week: celery

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Coming up in August — start thinking about
  • First harvests: celery
  • 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.

Grundy County, Illinois is in USDA Zone 5b. The average last spring frost is April 20 and the first fall frost is October 17, giving you a growing season of approximately 180 days.

At an elevation of 629 feet, Grundy County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Celery during the growing season.

Grundy County, IL (Zone 5b) Moderate season
180 days
Last Spring Frost April 20
180 growing days
First Fall Frost October 17

Grundy County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7

Drainage

Well Drained

Monthly Watering Guide for Celery

Celery needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Celery Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 3.3" 1" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 2.7" 1.6" 💧 Light watering
Oct 4.3" 2" 2.3" 🚿 Regular watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

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

Celery Planting Timeline — Grundy County, IL

Celery Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 6 Apr 6 – Apr 27
Harvest July 13 Jul 13 – Sep 7
Fall Sowing August 8 Aug 8 – Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

High — keep soil consistently moist

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

180 days in Grundy County

Growing Tips for Grundy 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celery in Grundy County, IL?

Grundy County is in Zone 5b with an average last frost of April 20. Plan your Celery planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grundy County, IL?

Grundy County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 20 and first fall frost is October 17.

When should I plant Celery in Grundy County, IL?

In Grundy County, IL, plant Celery after the last frost (around April 20) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Grundy County, IL for Celery?

Grundy County sits in USDA Zone 5b. Celery grows reliably in zones 2a through 10b, so it's a good fit here.

Can Celery grow in Grundy County's climate?

Yes — Celery grows well in Grundy County's temperate climate. Grundy County averages a 180-day frost-free season, with last frost around April 20 and first frost around October 17.

🌱

Your Grundy County Garden Planner — Free

A 22-page printable planner built for Grundy County (Zone 5b). 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 Grundy County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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