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When to Plant Celery in Jerome County, ID

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.

Jerome County, Idaho is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.

At an elevation of 6,306 feet, Jerome County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Celery during the growing season. With low rainfall, drip irrigation is essential for growing Celery successfully. Mulch heavily to conserve soil moisture.

Jerome County, ID (Zone 6a) Short season
147 days
Last Spring Frost May 10
147 growing days
First Fall Frost October 4

Jerome County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (10 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jul 24 – Sep 18
Recommended (50%) ✓ Fits season (7 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Aug 2 – Sep 27
Safe Start (90%) ✓ Fits season (0 days to spare)
Start indoors: Apr 30 Transplant: Jun 4 🍅 Harvest: Aug 27 – Oct 22

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
0.4″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 1,749 gal / 100 sq ft
Drought risk

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

Celery needs ~1,375 GDD — county provides 2,021 GDD Excellent fit

Celery Planting Timeline โ€” Jerome County, ID

Celery Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 โ€“ Apr 19
Transplant Outdoors May 10 May 10 โ€“ May 24
Direct Sow April 26 Apr 26 โ€“ May 17
Fall Sowing July 26 Jul 26 โ€“ Aug 9
Harvest August 2 Aug 2 โ€“ Sep 27

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Fall Sowing
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 6a

Growing Season

147 days

Growing Tips for Jerome 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 Jerome County, ID?

Jerome County is in Zone 6a with an average last frost of May 10. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jerome County, ID?

Jerome County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jerome County gardeners in Zone 6a 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 Jerome County, ID. Local conditions may vary. Last updated: April 2026.