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When to Plant Celery in Ventura County, CA

Ventura County, California Zone 10a April

April in the garden — Ventura County, California

Your garden in Ventura County, California is working on a schedule, even when you're not. Here's where you should be this April.

Avg. last frost March 18
Avg. first frost November 15
Soil temp (4") 67°F
Watering High
Pest pressure High
Daylight 12.9 hrs
  1. Start celery under lights

    Your window is short. These crops want several weeks of indoor growth before they go outside.

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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.

Ventura County, California is in USDA Zone 10a. The average last spring frost is March 18 and the first fall frost is November 15, giving you a growing season of approximately 242 days.

At an elevation of 2,094 feet, Ventura County receives approximately 19.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, 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.

Ventura County, CA (Zone 10a) Long season
242 days
Last Spring Frost March 18
242 growing days
First Fall Frost November 15

Ventura County Soil Profile

Soil Type

Loam

Soil pH

6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Feb 1 Transplant: Mar 1 🍅 Harvest: May 24 – Jul 19
Recommended (50%) ✓ Fits season (102 days to spare)
Start indoors: Feb 18 Transplant: Mar 18 🍅 Harvest: Jun 10 – Aug 5
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Mar 15 Transplant: Apr 12 🍅 Harvest: Jul 5 – Aug 30

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 Ventura County

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

Soil pH

Your soil pH (6.0–7.7) overlaps with Celery's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Ventura County is excellent for Celery — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Celery.

How to Plant Celery

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Celery

3
successive plantings in your 242-day season

Sow every 9.1 weeks. Last sowing by Jul 18 to harvest before frost.

For a dedicated fall crop, sow by Sep 20.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.3″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 2,490 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Celery

Celery needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Celery Needs Rainfall You Supplement Action
Jan 3.8" 0" ❄️ Dormant
Feb 4.4" 0" ❄️ Dormant
Mar 5.6" 3.2" 2.4" 💧 Light watering
Apr 5.6" 1.5" 4.1" 🚿 Regular watering
May 5.6" 0.6" 5" 🚿 Regular watering
Jun 5.6" 0.1" 5.5" 🚿 Regular watering
Jul 5.6" 0" 5.6" 🚿 Regular watering
Aug 5.6" 0" 5.6" 🚿 Regular watering
Sep 5.6" 0.2" 5.4" 🚿 Regular watering
Oct 5.6" 0.8" 4.8" 🚿 Regular watering
Nov 5.6" 1.7" 3.9" 🚿 Regular watering
Dec 3.1" 0" ❄️ Dormant

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

Celery Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Celery needs ~1,600 GDD — county provides 3,872 GDD Excellent fit

Celery Planting Timeline — Ventura County, CA

Celery Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors March 18 Mar 18 – Apr 1
Direct Sow February 25 Feb 25 – Mar 18
Harvest June 10 Jun 10 – Aug 5
Fall Sowing September 20 Sep 20 – Oct 4

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · 2-3 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 10a

📆 Growing Season

242 days in Ventura County

Growing Tips for Celery in Ventura County

Direct sow Celery outdoors after March 18 in Ventura 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.

Ventura County receives only 19" of rain annually. Celery needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Celery in Ventura County, CA?

Ventura County is in Zone 10a with an average last frost of March 18. Plan your Celery planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ventura County, CA?

Ventura County, California is in USDA Hardiness Zone 10a. The average last spring frost is March 18 and first fall frost is November 15.

🌱

Your Ventura County Garden Planner — Free

A 24-page printable planner built for Ventura County (Zone 10a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Ventura County, CA. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.