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When to Plant Celery in Del Norte County, CA

Del Norte County, California Zone 9b May

This month in Del Norte County, California

A quick May briefing for Del Norte County, California gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 27
Avg. first frost November 20
Soil temp (4") 71°F
Watering Critical
Pest pressure High
Daylight 14.4 hrs
Looking ahead to June
  • First harvests: celery

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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.

Del Norte County, California is in USDA Zone 9b. The average last spring frost is March 27 and the first fall frost is November 20, giving you a growing season of approximately 238 days.

At an elevation of 72 feet, Del Norte County receives approximately 43.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 89°F, providing good warmth for Celery during the growing season. Sandy soil warms quickly in spring — great for early planting — but Celery will need more frequent watering and organic matter to retain nutrients.

Del Norte County, CA (Zone 9b) Long season
238 days
Last Spring Frost March 27
238 growing days
First Fall Frost November 20

Del Norte County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (97 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: May 28 – Jul 23
Recommended (50%) ✓ Fits season (98 days to spare)
Start indoors: Feb 27 Transplant: Mar 27 🍅 Harvest: Jun 19 – Aug 14
Safe Start (90%) ✓ Fits season (87 days to spare)
Start indoors: Apr 6 Transplant: May 4 🍅 Harvest: Jul 27 – Sep 21

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 Del Norte County

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

Soil pH

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

Soil Texture

Sandy soil in Del Norte County warms quickly in spring but drains fast. Celery will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.7%). 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 238-day season

Sow every 9.1 weeks. Last sowing by Jul 23 to harvest before frost.

For a dedicated fall crop, sow by Sep 25.

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,116 gal / 100 sq ft

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 8.3" 0" ❄️ Dormant
Feb 9.9" 0" ❄️ Dormant
Mar 5.6" 5.8" 0" ✅ Rainfall sufficient
Apr 5.6" 3.5" 2.1" 💧 Light watering
May 5.6" 1.1" 4.5" 🚿 Regular watering
Jun 5.6" 0.3" 5.3" 🚿 Regular watering
Jul 5.6" 0" 5.6" 🚿 Regular watering
Aug 5.6" 0" 5.6" 🚿 Regular watering
Sep 5.6" 0.4" 5.2" 🚿 Regular watering
Oct 5.6" 1.9" 3.7" 🚿 Regular watering
Nov 5.6" 4.7" 0.9" 💧 Light watering
Dec 7.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Del Norte 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 ~1,675 GDD — county provides 3,986 GDD Excellent fit

Celery Planting Timeline — Del Norte County, CA

Celery Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 6 Mar 6 – Mar 27
Harvest June 19 Jun 19 – Aug 14
Fall Sowing September 25 Sep 25 – Oct 9

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
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 · 1-2 times/week

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

238 days in Del Norte County

Growing Tips for Celery in Del Norte County

Direct sow Celery outdoors after March 27 in Del Norte County when soil has warmed and frost danger has passed.

Sandy soil in Del Norte County dries quickly — mulch Celery with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

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 Del Norte County, CA?

Del Norte County is in Zone 9b with an average last frost of March 27. Plan your Celery planting based on this frost date — see the calendar above for exact timing.

What planting zone is Del Norte County, CA?

Del Norte County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 27 and first fall frost is November 20.

🌱

Your Del Norte County Garden Planner — Free

A 24-page printable planner built for Del Norte 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.

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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 Del Norte County, CA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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