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When to Plant Celery in Colusa 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.

Colusa County, California is in USDA Zone 9a. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.

At an elevation of 112 feet, Colusa County receives approximately 29.8 inches of rainfall annually with predominantly loam soil. Summer highs average 94Β°F, providing good warmth for Celery during the growing season.

Colusa County, CA (Zone 9a) Long season
267 days
Last Spring Frost March 6
267 growing days
First Fall Frost November 28

Colusa County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.5

Drainage

Well Drained

Monthly Watering Guide for Celery

Celery needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Celery Needs Rainfall You Supplement Action
Jan β€” 6.2" 0" ❄️ Dormant
Feb β€” 6.7" 0" ❄️ Dormant
Mar 4.3" 4.7" 0" βœ… Rainfall sufficient
Apr 4.3" 2" 2.3" 🚿 Regular watering
May 4.3" 0.7" 3.6" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 4.3" 3" 1.3" πŸ’§ Light watering
Dec β€” 4.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Colusa County). Supplement amounts are based on average rainfall β€” actual needs vary with temperature, soil, and mulching.

Celery Planting Timeline β€” Colusa County, CA

Celery Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors March 6 Mar 6 – Mar 20
Direct Sow February 13 Feb 13 – Mar 6
Harvest May 29 May 29 – Jul 24
Fall Sowing October 3 Oct 3 – Oct 17

Plant 1" deep Β· 15" apart Β· Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

β˜€οΈ Sun

Full Sun (6-8+ hours)

πŸ’§ Water

High β€” keep soil consistently moist

πŸ“… Days to Maturity

80–120 days

πŸ§ͺ Soil pH

Needs 6–7 Β· Your soil: N/A

πŸ—ΊοΈ USDA Zone

Zone 9a

πŸ“† Growing Season

267 days in Colusa County

Growing Tips for Colusa 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celery in Colusa County, CA?

Colusa County is in Zone 9a with an average last frost of March 6. Plan your Celery planting based on this frost date β€” see the calendar above for exact timing.

What planting zone is Colusa County, CA?

Colusa County, California is in USDA Hardiness Zone 9a. The average last spring frost is March 6 and first fall frost is November 28.

🌱

Plan Your Garden with Confidence

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