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When to Plant Celery in Dubuque County, IA

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.

Dubuque County, Iowa is in USDA Zone 4b. The average last spring frost is April 29 and the first fall frost is October 9, giving you a growing season of approximately 163 days.

At an elevation of 1,243 feet, Dubuque County receives approximately 36.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Celery to ensure they mature before fall.

Dubuque County, IA (Zone 4b) Moderate season
163 days
Last Spring Frost April 29
163 growing days
First Fall Frost October 9

Dubuque County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Start indoors: Mar 13 Transplant: Apr 24 🍅 Harvest: Jul 17 – Sep 11
Recommended (50%) ✓ Fits season (23 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🍅 Harvest: Jul 22 – Sep 16
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Aug 7 – Oct 2

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 Dubuque County

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

Soil pH

Your soil pH (5.8โ€“7.3) overlaps with Celery's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Dubuque County is excellent for Celery โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Celery.

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.

Succession Planting Celery

2
successive plantings in your 163-day season

Sow every 9.1 weeks. Last sowing by Jun 11 to harvest before frost.

For a dedicated fall crop, sow by Jul 17.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.9″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,300 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr 5.6" 3.4" 2.2" ๐Ÿ’ง Light watering
May 5.6" 4.1" 1.5" ๐Ÿ’ง Light watering
Jun 5.6" 4.8" 0.8" ๐Ÿ’ง Light watering
Jul 5.6" 4.3" 1.3" ๐Ÿ’ง Light watering
Aug 5.6" 3.5" 2.1" ๐Ÿ’ง Light watering
Sep 5.6" 3.2" 2.4" ๐Ÿ’ง Light watering
Oct 5.6" 3.3" 2.3" ๐Ÿ’ง Light watering
Nov โ€” 2.6" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Dubuque County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,225 GDD — county provides 1,996 GDD Excellent fit

Celery Planting Timeline โ€” Dubuque County, IA

Celery Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 โ€“ Apr 1
Transplant Outdoors April 29 Apr 29 โ€“ May 13
Direct Sow April 22 Apr 22 โ€“ May 13
Harvest July 22 Jul 22 โ€“ Sep 16
Fall Sowing July 17 Jul 17 โ€“ Jul 31

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.3"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

163 days in Dubuque County

Growing Tips for Celery in Dubuque County

Direct sow Celery outdoors after April 29 in Dubuque 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 Dubuque County, IA?

Dubuque County is in Zone 4b with an average last frost of April 29. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dubuque County, IA?

Dubuque County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 29 and first fall frost is October 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dubuque County gardeners in Zone 4b 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 Dubuque County, IA. Local conditions may vary. Last updated: April 2026.