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When to Plant Celery in San Bernardino 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.

San Bernardino County, California is in USDA Zone 9a. The average last spring frost is February 24 and the first fall frost is November 25, giving you a growing season of approximately 274 days.

At an elevation of 1,012 feet, San Bernardino County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 97ยฐF, so Celery may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Celery successfully. Mulch heavily to conserve soil moisture.

San Bernardino County, CA (Zone 9a) Year-round
274 days
Last Spring Frost February 24
274 growing days
First Fall Frost November 25

San Bernardino County Soil Profile

Soil Type

Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (140 days to spare)
Start indoors: Jan 16 Transplant: Feb 13 🍅 Harvest: May 8 – Jul 3
Recommended (50%) ✓ Fits season (134 days to spare)
Start indoors: Jan 27 Transplant: Feb 24 🍅 Harvest: May 19 – Jul 14
Safe Start (90%) ✓ Fits season (137 days to spare)
Start indoors: Feb 7 Transplant: Mar 7 🍅 Harvest: May 30 – Jul 25

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 San Bernardino County

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

Soil pH

Your soil pH (5.9โ€“7.2) overlaps with Celery's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The loam soil in San Bernardino County is excellent for Celery โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). 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

4
successive plantings in your 274-day season

Sow every 9.1 weeks. Last sowing by Jul 28 to harvest before frost.

For a dedicated fall crop, sow by Sep 30.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.3″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 3,060 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” 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 โ€” 3.2" 0" โ„๏ธ Dormant
Feb 5.6" 3.8" 1.8" ๐Ÿ’ง Light watering
Mar 5.6" 2.2" 3.4" ๐Ÿšฟ Regular watering
Apr 5.6" 1.5" 4.1" ๐Ÿšฟ Regular watering
May 5.6" 0.5" 5.1" ๐Ÿšฟ Regular watering
Jun 5.6" 0.1" 5.5" ๐Ÿšฟ Regular watering
Jul 5.6" 0" 5.6" ๐Ÿšฟ Regular watering
Aug 5.6" 0" 5.6" ๐Ÿšฟ Regular watering
Sep 5.6" 0.2" 5.4" ๐Ÿšฟ Regular watering
Oct 5.6" 0.7" 4.9" ๐Ÿšฟ Regular watering
Nov 5.6" 1.7" 3.9" ๐Ÿšฟ Regular watering
Dec โ€” 3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Febโ€“Nov in San Bernardino County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~2,275 GDD — county provides 6,256 GDD Excellent fit

Celery Planting Timeline โ€” San Bernardino County, CA

Celery Planting Calendar

Activity When Date Range
Start Indoors January 27 Jan 27 โ€“ Feb 10
Transplant Outdoors February 24 Feb 24 โ€“ Mar 10
Direct Sow February 3 Feb 3 โ€“ Feb 24
Harvest May 19 May 19 โ€“ Jul 14
Fall Sowing September 30 Sep 30 โ€“ Oct 14

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.3"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

80โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

274 days in San Bernardino County

Growing Tips for Celery in San Bernardino County

Direct sow Celery outdoors after February 24 in San Bernardino County when soil has warmed and frost danger has passed.

With summer highs reaching 97ยฐF in San Bernardino County, provide afternoon shade for Celery and water deeply in the morning.

Common pests for Celery in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

San Bernardino County receives only 17" of rain annually. Celery needs consistent moisture โ€” 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 San Bernardino County, CA?

San Bernardino County is in Zone 9a with an average last frost of February 24. Plan your Celery planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Bernardino County, CA?

San Bernardino County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 24 and first fall frost is November 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Bernardino 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 San Bernardino County, CA. Local conditions may vary. Last updated: April 2026.