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When to Plant Cauliflower in Mineral 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.

Mineral County, Colorado is in USDA Zone 4a. The average last spring frost is June 10 and the first fall frost is September 13, giving you a growing season of approximately 95 days.

At an elevation of 7,809 feet, Mineral County receives approximately 12.8 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Cauliflower to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Cauliflower successfully. Mulch heavily to conserve soil moisture.

Mineral County, CO (Zone 4a) Very short season
95 days
Last Spring Frost June 10
95 growing days
First Fall Frost September 13

Mineral County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 17 Transplant: May 29 🍅 Harvest: Jul 24 – Sep 25
Recommended (50%) ✗ May not fit
Start indoors: Apr 29 Transplant: Jun 10 🍅 Harvest: Aug 5 – Oct 7
Safe Start (90%) ✗ May not fit
Start indoors: May 15 Transplant: Jun 26 🍅 Harvest: Aug 21 – Oct 23

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 Mineral County

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

Soil pH

Your soil pH (6.8โ€“8.0) is more alkaline than Cauliflower prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Cauliflower is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

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 Mineral County's 95-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
0.6″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 745 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" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.2" 0" โ„๏ธ Dormant
Apr โ€” 1.1" 0" โ„๏ธ Dormant
May โ€” 1.6" 0" โ„๏ธ Dormant
Jun 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Jul 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Aug 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Sep 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Oct โ€” 1.2" 0" โ„๏ธ Dormant
Nov โ€” 0.9" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Mineral 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 ~775 GDD — county provides 950 GDD Good fit

Cauliflower Planting Timeline โ€” Mineral County, CO

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors April 29 Apr 29 โ€“ May 13
Transplant Outdoors June 10 Jun 10 โ€“ Jun 24
Direct Sow June 3 Jun 3 โ€“ Jun 24
Harvest August 5 Aug 5 โ€“ Oct 7
Fall Sowing June 21 Jun 21 โ€“ Jul 5

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May Start Indoors
June Transplant Outdoors Direct Sow Fall Sowing
July Fall Sowing
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 2-3 times/week

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

95 days in Mineral County

Growing Tips for Cauliflower in Mineral County

Direct sow Cauliflower outdoors after June 10 in Mineral County when soil has warmed and frost danger has passed.

Your 95.0-day growing season in Mineral 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.

Mineral County receives only 13" 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 Mineral County, CO?

Mineral County is in Zone 4a with an average last frost of June 10. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mineral County, CO?

Mineral County, Colorado is in USDA Hardiness Zone 4a. The average last spring frost is June 10 and first fall frost is September 13.

๐ŸŒฑ

Plan Your Garden with Confidence

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