Blog

When to Plant Celery in Adams 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.

Adams County, Iowa is in USDA Zone 5a. The average last spring frost is April 24 and the first fall frost is October 11, giving you a growing season of approximately 170 days.

At an elevation of 998 feet, Adams County receives approximately 32.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Celery during the growing season.

Adams County, IA (Zone 5a) Moderate season
170 days
Last Spring Frost April 24
170 growing days
First Fall Frost October 11

Adams County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jul 11 – Sep 5
Recommended (50%) ✓ Fits season (30 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jul 17 – Sep 11
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Apr 3 Transplant: May 8 🍅 Harvest: Jul 31 – Sep 25

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 Adams County

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

Soil pH

Your soil pH (6.1โ€“7.2) overlaps with Celery's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.8%) โ€” Celery will thrive.

How to Plant Celery

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

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

Succession Planting Celery

2
successive plantings in your 170-day season

Sow every 9.1 weeks. Last sowing by Jun 13 to harvest before frost.

For a dedicated fall crop, sow by Aug 02.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 920 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 2,465 GDD Excellent fit

Celery Planting Timeline โ€” Adams County, IA

Celery Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 โ€“ Apr 3
Transplant Outdoors April 24 Apr 24 โ€“ May 8
Direct Sow April 10 Apr 10 โ€“ May 1
Fall Sowing August 2 Aug 2 โ€“ Aug 16
Harvest July 17 Jul 17 โ€“ Sep 11

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 Harvest
August Fall Sowing 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 1-2 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 5a

๐Ÿ“† Growing Season

170 days in Adams County

Growing Tips for Celery in Adams County

Direct sow Celery outdoors after April 24 in Adams 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Celery in Adams County, IA?

Adams County is in Zone 5a with an average last frost of April 24. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Adams County, IA?

Adams County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 24 and first fall frost is October 11.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Adams County, IA. Local conditions may vary. Last updated: April 2026.