Blog

When to plant Celery in San Joaquin County, CA

Celery planted in San Joaquin County between January 14 and February 4 matures in 80–120 days — well before the December 6 first frost. A second sowing from October 11 to October 25 extends the harvest into fall.

When to Plant Celery in San Joaquin County, CA

Celery

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.

San Joaquin County, California is in USDA Zone 9b. The average last spring frost is February 4 and the first fall frost is December 6, giving you a growing season of approximately 305 days.

At an elevation of 220 feet, San Joaquin County receives approximately 15 inches of rainfall annually with predominantly loam soil. Summer highs average 93°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.

San Joaquin County, CA (Zone 9b) Year-round
305 days
Last Spring Frost February 4
305 growing days
First Fall Frost December 6

San Joaquin County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.8

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 2.9" 0" ❄️ Dormant
Feb 4.3" 3.1" 1.2" 💧 Light watering
Mar 4.3" 2.6" 1.7" 💧 Light watering
Apr 4.3" 1.2" 3.1" 🚿 Regular watering
May 4.3" 0.4" 3.9" 🚿 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" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.7" 3.6" 🚿 Regular watering
Nov 4.3" 1.3" 3" 🚿 Regular watering
Dec 4.3" 2.6" 1.7" 💧 Light watering

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

Celery Planting Timeline — San Joaquin County, CA

Celery Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 – Jan 21
Transplant Outdoors February 4 Feb 4 – Feb 18
Direct Sow January 14 Jan 14 – Feb 4
Harvest April 29 Apr 29 – Jun 24
Fall Sowing October 11 Oct 11 – Oct 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

High — keep soil consistently moist

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

305 days in San Joaquin County

Growing Tips for San Joaquin 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 San Joaquin County, CA?

San Joaquin County is in Zone 9b with an average last frost of February 4. Plan your Celery planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Joaquin County, CA?

San Joaquin County, California is in USDA Hardiness Zone 9b. The average last spring frost is February 4 and first fall frost is December 6.

When should I plant Celery in San Joaquin County, CA?

In San Joaquin County, CA, plant Celery after the last frost (around February 4) and before the first frost (around December 6). Best results when soil holds above 50°F.

What growing zone is San Joaquin County, CA for Celery?

San Joaquin County sits in USDA Zone 9b. Celery grows reliably in zones 2a through 10b, so it's a good fit here.

Can Celery grow in San Joaquin County's climate?

Yes — Celery grows well in San Joaquin County's temperate climate. San Joaquin County averages a 306-day frost-free season, with last frost around February 4 and first frost around December 6.

🌱

Your San Joaquin County Garden Planner — Free

A 22-page printable planner built for San Joaquin County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for San Joaquin County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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