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When to Plant Corn in Orange County, CA

Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.

Orange County, California is in USDA Zone 10a. The average last spring frost is February 13 and the first fall frost is December 11, giving you a growing season of approximately 301 days.

At an elevation of 405 feet, Orange County receives approximately 13.8 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Corn during the growing season. With low rainfall, drip irrigation is essential for growing Corn successfully. Mulch heavily to conserve soil moisture.

Orange County, CA (Zone 10a) Year-round
301 days
Last Spring Frost February 13
301 growing days
First Fall Frost December 11

Orange County Soil Profile

Soil Type

Loam

Soil pH

5.7-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (181 days to spare)
Transplant: Feb 2 🍅 Harvest: Apr 6 – Jun 1
Recommended (50%) ✓ Fits season (182 days to spare)
Transplant: Feb 13 🍅 Harvest: Apr 17 – Jun 12
Safe Start (90%) ✓ Fits season (143 days to spare)
Transplant: Apr 2 🍅 Harvest: Jun 4 – Jul 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 Orange County

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

Soil pH

Your soil pH (5.7โ€“7.6) overlaps with Corn's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Corn.

How to Plant Corn

1"
Planting Depth
12"
Between Plants
36"
Between Rows

Succession Planting Corn

6
successive plantings in your 301-day season

Sow every 6.9 weeks. Last sowing by Sep 02 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.2″/week
You supply
1.6″/week
Watering frequency 2-3 times/week
Season total 4,219 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Corn

Corn needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Corn Needs Rainfall You Supplement Action
Jan โ€” 2.4" 0" โ„๏ธ Dormant
Feb 6.5" 2.6" 3.9" ๐Ÿšฟ Regular watering
Mar 6.5" 2.2" 4.3" ๐Ÿšฟ Regular watering
Apr 6.5" 1.1" 5.4" ๐Ÿšฟ Regular watering
May 6.5" 0.4" 6.1" ๐Ÿšฟ Regular watering
Jun 6.5" 0.1" 6.4" ๐Ÿšฟ Regular watering
Jul 6.5" 0" 6.5" ๐Ÿšฟ Regular watering
Aug 6.5" 0" 6.5" ๐Ÿšฟ Regular watering
Sep 6.5" 0.2" 6.3" ๐Ÿšฟ Regular watering
Oct 6.5" 0.7" 5.8" ๐Ÿšฟ Regular watering
Nov 6.5" 1.5" 5" ๐Ÿšฟ Regular watering
Dec 6.5" 2.7" 3.8" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Orange County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Corn 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.

Corn needs ~1,280 GDD — county provides 4,832 GDD Excellent fit

Corn Planting Timeline โ€” Orange County, CA

Corn Planting Calendar

Activity When Date Range
Direct Sow February 20 Feb 20 โ€“ Mar 13
Harvest April 24 Apr 24 โ€“ Jun 19

Plant 1" deep ยท 12" apart ยท Rows 36" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Direct Sow
March Direct Sow
April Harvest
May Harvest
June Harvest
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.5"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 10a

๐Ÿ“† Growing Season

301 days in Orange County

Growing Tips for Corn in Orange County

Direct sow Corn outdoors after February 13 in Orange County when soil has warmed and frost danger has passed.

Common pests for Corn in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

Orange County receives only 14" of rain annually. Corn needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Celery

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Corn in Orange County, CA?

Orange County is in Zone 10a with an average last frost of February 13. Plan your Corn planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Orange County, CA?

Orange County, California is in USDA Hardiness Zone 10a. The average last spring frost is February 13 and first fall frost is December 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Orange County gardeners in Zone 10a 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 Orange County, CA. Local conditions may vary. Last updated: April 2026.