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When to Plant Celery in Butte County, CA

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.

Butte County, California is in USDA Zone 9a. The average last spring frost is April 20 and the first fall frost is November 10, giving you a growing season of approximately 204 days.

At an elevation of 144 feet, Butte County receives approximately 44.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Celery during the growing season.

Butte County, CA (Zone 9a) Long season
204 days
Last Spring Frost April 20
204 growing days
First Fall Frost November 10

Butte County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Start indoors: Feb 26 Transplant: Mar 26 🍅 Harvest: Jun 18 – Aug 13
Recommended (50%) ✓ Fits season (64 days to spare)
Start indoors: Mar 23 Transplant: Apr 20 🍅 Harvest: Jul 13 – Sep 7
Safe Start (90%) ✓ Fits season (64 days to spare)
Start indoors: Apr 26 Transplant: May 24 🍅 Harvest: Aug 16 – Oct 11

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
0.9″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 2,239 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Celery needs ~1,750 GDD — county provides 3,570 GDD Excellent fit

Celery Planting Timeline โ€” Butte County, CA

Celery Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 โ€“ Apr 6
Transplant Outdoors April 20 Apr 20 โ€“ May 4
Direct Sow March 30 Mar 30 โ€“ Apr 20
Fall Sowing September 15 Sep 15 โ€“ Sep 29
Harvest July 13 Jul 13 โ€“ Sep 7

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors Direct Sow
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors
June โ€”
July Harvest
August Harvest
September Fall Sowing 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 9a

Growing Season

204 days

Growing Tips for Butte 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 Butte County, CA?

Butte County is in Zone 9a with an average last frost of April 20. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Butte County, CA?

Butte County, California is in USDA Hardiness Zone 9a. The average last spring frost is April 20 and first fall frost is November 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Butte County gardeners in Zone 9a 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 Butte County, CA. Local conditions may vary. Last updated: April 2026.