Blog

When to Plant Cauliflower in Imperial County, CA

Cauliflower is a cool-season brassica that produces dense white, purple, or green heads called curds. It is more finicky than broccoli but rewards with a mild, nutty flavor.

Imperial County, California is in USDA Zone 10a. The average last spring frost is January 29 and the first fall frost is December 20, giving you a growing season of approximately 325 days.

At an elevation of 181 feet, Imperial County receives approximately 16.8 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Cauliflower during the growing season. With low rainfall, drip irrigation is essential for growing Cauliflower successfully. Mulch heavily to conserve soil moisture.

Imperial County, CA (Zone 10a) Year-round
325 days
Last Spring Frost January 29
325 growing days
First Fall Frost December 20

Imperial County Soil Profile

Soil Type

Loam

Soil pH

5.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (214 days to spare)
Start indoors: Dec 19 Transplant: Jan 16 🍅 Harvest: Mar 13 – May 15
Recommended (50%) ✓ Fits season (206 days to spare)
Start indoors: Jan 1 Transplant: Jan 29 🍅 Harvest: Mar 26 – May 28
Safe Start (90%) ✓ Fits season (197 days to spare)
Start indoors: Jan 17 Transplant: Feb 14 🍅 Harvest: Apr 11 – Jun 13

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 Imperial County

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

Soil pH

Your soil pH (5.7โ€“7.3) overlaps with Cauliflower's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

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

How to Plant Cauliflower

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 Cauliflower

7
successive plantings in your 325-day season

Sow every 6.3 weeks. Last sowing by Sep 11 to harvest before frost.

For a dedicated fall crop, sow by Oct 25.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 2,728 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Cauliflower

Cauliflower needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Cauliflower Needs Rainfall You Supplement Action
Jan 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Feb 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Mar 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Apr 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
May 4.3" 0.4" 3.9" ๐Ÿšฟ Regular watering
Jun 4.3" 0.1" 4.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Oct 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Nov 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Dec 4.3" 3.3" 1" ๐Ÿ’ง Light watering

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

Cauliflower 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.

Cauliflower needs ~1,531 GDD — county provides 6,438 GDD Excellent fit

Cauliflower Planting Timeline โ€” Imperial County, CA

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors January 1 Jan 1 โ€“ Jan 15
Transplant Outdoors January 29 Jan 29 โ€“ Feb 12
Direct Sow January 8 Jan 8 โ€“ Jan 29
Harvest March 26 Mar 26 โ€“ May 28
Fall Sowing October 25 Oct 25 โ€“ Nov 8

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 10a

๐Ÿ“† Growing Season

325 days in Imperial County

Growing Tips for Cauliflower in Imperial County

Direct sow Cauliflower outdoors after January 29 in Imperial County when soil has warmed and frost danger has passed.

Summer highs in Imperial County reach 93ยฐF โ€” grow Cauliflower as a spring or fall crop. Use shade cloth if planting in summer.

Common pests for Cauliflower in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Imperial County receives only 17" of rain annually. Cauliflower needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 6 weeks before transplanting. Blanch white varieties by tying outer leaves over the head. Provide consistent moisture and avoid temperature extremes.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cauliflower in Imperial County, CA?

Imperial County is in Zone 10a with an average last frost of January 29. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Imperial County, CA?

Imperial County, California is in USDA Hardiness Zone 10a. The average last spring frost is January 29 and first fall frost is December 20.

๐ŸŒฑ

Plan Your Garden with Confidence

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