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When to Plant Cauliflower in Eagle County, CO

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.

Eagle County, Colorado is in USDA Zone 4b. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 7,116 feet, Eagle County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Cauliflower to ensure they mature before fall.

Eagle County, CO (Zone 4b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

Eagle County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 24 Transplant: Jun 5 🍅 Harvest: Jul 31 – Oct 2
Recommended (50%) ✗ May not fit
Start indoors: May 5 Transplant: Jun 16 🍅 Harvest: Aug 11 – Oct 13
Safe Start (90%) ✗ May not fit
Start indoors: May 16 Transplant: Jun 27 🍅 Harvest: Aug 22 – Oct 24

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 Eagle County

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

Soil pH

Your soil pH (6.6โ€“7.7) is more alkaline than Cauliflower prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Cauliflower.

How to Plant Cauliflower

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

How Much Cauliflower to Grow

1-2 lbs
Average yield per plant
3
Plants per person
7.5 sq ft
Space per person

For a family of 4, plant approximately 12 cauliflower plants in about 30 sq ft. In Eagle County's 83-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 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 โ€” 1.8" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr โ€” 2.8" 0" โ„๏ธ Dormant
May โ€” 3.2" 0" โ„๏ธ Dormant
Jun 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering
Jul 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Aug 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Sep 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Oct โ€” 2" 0" โ„๏ธ Dormant
Nov โ€” 1.6" 0" โ„๏ธ Dormant
Dec โ€” 1.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Eagle 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 ~833 GDD — county provides 892 GDD Good fit

Cauliflower Planting Timeline โ€” Eagle County, CO

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors May 5 May 5 โ€“ May 19
Transplant Outdoors June 16 Jun 16 โ€“ Jun 30
Direct Sow June 9 Jun 9 โ€“ Jun 30
Harvest August 11 Aug 11 โ€“ Oct 13
Fall Sowing June 15 Jun 15 โ€“ Jun 29

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

83 days in Eagle County

Growing Tips for Cauliflower in Eagle County

Direct sow Cauliflower outdoors after June 16 in Eagle County when soil has warmed and frost danger has passed.

Your 83.0-day growing season in Eagle County is tight for Cauliflower (55.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

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

Eagle County receives only 24" 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 Eagle County, CO?

Eagle County is in Zone 4b with an average last frost of June 16. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Eagle County, CO?

Eagle County, Colorado is in USDA Hardiness Zone 4b. The average last spring frost is June 16 and first fall frost is September 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Eagle County gardeners in Zone 4b 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 Eagle County, CO. Local conditions may vary. Last updated: April 2026.