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When to plant Cauliflower in Jackson County, CO

Jackson County's climate puts the Cauliflower spring window between June 6 and June 27. be cautious and check the 10-day forecast before planting tender crops. A second sowing from June 12 to June 26 extends the harvest into fall.

When to Plant Cauliflower in Jackson County, CO

Cauliflower

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.

Jackson County, Colorado is in USDA Zone 4b. The average last spring frost is June 13 and the first fall frost is September 4, giving you a growing season of approximately 83 days.

At an elevation of 5,388 feet, Jackson County receives approximately 20.9 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Cauliflower to ensure they mature before fall.

Jackson County, CO (Zone 4b) Very short season
83 days
Last Spring Frost June 13
83 growing days
First Fall Frost September 4

Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

How Much Cauliflower to Grow

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

For a family of 4, plant approximately 12 cauliflower plants in about 24 sq ft. In Jackson County's 83-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Cauliflower Planting Timeline — Jackson County, CO

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors May 2 May 2 – May 16
Transplant Outdoors June 13 Jun 13 – Jun 27
Direct Sow June 6 Jun 6 – Jun 27
Harvest August 8 Aug 8 – Oct 10
Fall Sowing June 12 Jun 12 – Jun 26

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

High — keep soil consistently moist

📅 Days to Maturity

55–100 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4b

📆 Growing Season

83 days in Jackson County

Growing Tips for Jackson County

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 Jackson County, CO?

Jackson County is in Zone 4b with an average last frost of June 13. Plan your Cauliflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, CO?

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

When should I plant Cauliflower in Jackson County, CO?

In Jackson County, CO, plant Cauliflower after the last frost (around June 13) and before the first frost (around September 4). Best results when soil holds above 50°F.

What growing zone is Jackson County, CO for Cauliflower?

Jackson County sits in USDA Zone 4b. Cauliflower grows reliably in zones 2a through 10b, so it's a good fit here.

Can Cauliflower grow in Jackson County's climate?

Yes — Cauliflower grows well in Jackson County's temperate climate. Jackson County averages a 83-day frost-free season, with last frost around June 13 and first frost around September 4.

🌱

Your Jackson County Garden Planner — Free

A 22-page printable planner built for Jackson County (Zone 4b). 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 Jackson County, CO. Local conditions may vary. Last updated: June 2026.

Sources & credits

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