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When to Plant Celery in Union County, SD

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.

Union County, South Dakota is in USDA Zone 5a. The average last spring frost is April 30 and the first fall frost is October 5, giving you a growing season of approximately 158 days.

At an elevation of 938 feet, Union County receives approximately 22.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Celery during the growing season.

Union County, SD (Zone 5a) Moderate season
158 days
Last Spring Frost April 30
158 growing days
First Fall Frost October 5

Union County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Jul 16 – Sep 10
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jul 23 – Sep 17
Safe Start (90%) ✓ Fits season (13 days to spare)
Start indoors: Apr 10 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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,508 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 2,291 GDD Excellent fit

Celery Planting Timeline โ€” Union County, SD

Celery Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 โ€“ Apr 9
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Direct Sow April 16 Apr 16 โ€“ May 7
Fall Sowing July 27 Jul 27 โ€“ Aug 10
Harvest July 23 Jul 23 โ€“ Sep 17

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 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 5a

Growing Season

158 days

Growing Tips for Union 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 Union County, SD?

Union County is in Zone 5a with an average last frost of April 30. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Union County, SD?

Union County, South Dakota is in USDA Hardiness Zone 5a. The average last spring frost is April 30 and first fall frost is October 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Union County gardeners in Zone 5a 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 Union County, SD. Local conditions may vary. Last updated: April 2026.