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When to Plant Carrots in San Diego County, CA

San Diego County, California Zone 10b May

May to-do list for San Diego County, California

Here's what deserves your attention in San Diego County, California this month. Everything below is tailored to Zone 10b and timed around your local frost dates.

Avg. last frost April 16
Avg. first frost November 1
Soil temp (4") 74°F
Watering Critical
Pest pressure High
Daylight 13.7 hrs
  1. Pick carrots

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Before June arrives, get these ready
  • First harvests: carrots

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Carrots are a popular root vegetable available in orange, purple, white, and yellow varieties. They are rich in beta-carotene and have a sweet, earthy flavor.

San Diego County, California is in USDA Zone 10b. The average last spring frost is April 16 and the first fall frost is November 1, giving you a growing season of approximately 199 days.

At an elevation of 2,613 feet, San Diego County receives approximately 18.2 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Carrots during the growing season. With low rainfall, drip irrigation is essential for growing Carrots successfully. Mulch heavily to conserve soil moisture.

San Diego County, CA (Zone 10b) Moderate season
199 days
Last Spring Frost April 16
199 growing days
First Fall Frost November 1

San Diego County Soil Profile

Soil Type

Loam

Soil pH

5.7-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (96 days to spare)
Transplant: Apr 9 🍅 Harvest: Jun 11 – Jul 16
Recommended (50%) ✓ Fits season (101 days to spare)
Transplant: Apr 16 🍅 Harvest: Jun 18 – Jul 23
Safe Start (90%) ✓ Fits season (97 days to spare)
Transplant: May 21 🍅 Harvest: Jul 23 – Aug 27

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 Diego County

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

Soil pH

Your soil pH (5.7–7.5) overlaps with Carrots's range (6.0–6.8), though not a perfect match.

Soil Texture

The loam soil in San Diego County is excellent for Carrots — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Carrots.

How to Plant Carrots

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Succession Planting Carrots

3
successive plantings in your 199-day season

Sow every 6.9 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Sep 06.

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.4″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 884 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Carrots

Carrots needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Carrots Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 3.1" 0" ❄️ Dormant
Apr 3.5" 1.4" 2.1" 🚿 Regular watering
May 3.5" 0.5" 3" 🚿 Regular watering
Jun 3.5" 0.1" 3.4" 🚿 Regular watering
Jul 3.5" 0" 3.5" 🚿 Regular watering
Aug 3.5" 0" 3.5" 🚿 Regular watering
Sep 3.5" 0.2" 3.3" 🚿 Regular watering
Oct 3.5" 0.8" 2.7" 🚿 Regular watering
Nov 3.5" 1.8" 1.7" 💧 Light watering
Dec 3.3" 0" ❄️ Dormant

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

Carrots 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.

Carrots needs ~1,330 GDD — county provides 3,781 GDD Excellent fit

Carrots Planting Timeline — San Diego County, CA

Carrots Planting Calendar

Activity When Date Range
Direct Sow March 26 Mar 26 – Apr 16
Harvest May 28 May 28 – Jul 2
Fall Sowing September 6 Sep 6 – Sep 20

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · 1-2 times/week

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–6.8 · Your soil: acceptable

🗺️ USDA Zone

Zone 10b

📆 Growing Season

199 days in San Diego County

Growing Tips for Carrots in San Diego County

Direct sow Carrots outdoors after April 16 in San Diego County when soil has warmed and frost danger has passed.

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

General growing tips

Sow seeds directly in loose, stone-free soil for straight roots. Keep soil moist until germination which can take 2-3 weeks. Thin seedlings to 2 inches apart.

Companion Planting

Good Companions

Avoid Planting Near

  • Dill
  • Parsnip

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Carrots Seeds
Life Cycle Biennial
Pollination Cross-Pollinated (insects)
How to Collect Replant roots for 2nd year flowers. Harvest umbels when brown.
Storage Store airtight; viable 3 years at 35°F, under 50% humidity.

Isolate 1/2 mile from Queen Anne's Lace (wild carrot). Biennial — requires two seasons.

Frequently Asked Questions

When should I plant Carrots in San Diego County, CA?

San Diego County is in Zone 10b with an average last frost of April 16. Plan your Carrots planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Diego County, CA?

San Diego County, California is in USDA Hardiness Zone 10b. The average last spring frost is April 16 and first fall frost is November 1.

🌱

Your San Diego County Garden Planner — Free

A 24-page printable planner built for San Diego County (Zone 10b). 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 San Diego 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.