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When to Plant Cauliflower in Cook County, MN

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.

Cook County, Minnesota is in USDA Zone 3a. The average last spring frost is May 20 and the first fall frost is September 29, giving you a growing season of approximately 132 days.

At an elevation of 1,068 feet, Cook County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Cauliflower to ensure they mature before fall.

Cook County, MN (Zone 3a) Short season
132 days
Last Spring Frost May 20
132 growing days
First Fall Frost September 29

Cook County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 10 – Sep 11
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Apr 8 Transplant: May 20 🍅 Harvest: Jul 15 – Sep 16
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Apr 19 Transplant: May 31 🍅 Harvest: Jul 26 – Sep 27

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 Cook County

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

Soil pH

Your soil pH (6.1โ€“7.1) overlaps with Cauliflower's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.4%) โ€” Cauliflower will thrive.

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.

Succession Planting Cauliflower

2
successive plantings in your 132-day season

Sow every 6.3 weeks. Last sowing by Jun 21 to harvest before frost.

For a dedicated fall crop, sow by Jul 07.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/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€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.5" 0" โ„๏ธ Dormant
Apr โ€” 3.5" 0" โ„๏ธ Dormant
May 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Jun 4.3" 4.7" 0" โœ… Rainfall sufficient
Jul 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Aug 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Sep 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Oct โ€” 2.7" 0" โ„๏ธ Dormant
Nov โ€” 2.5" 0" โ„๏ธ Dormant
Dec โ€” 2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Cook 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 1,320 GDD Excellent fit

Cauliflower Planting Timeline โ€” Cook County, MN

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 โ€“ Apr 22
Transplant Outdoors May 20 May 20 โ€“ Jun 3
Direct Sow May 13 May 13 โ€“ Jun 3
Harvest July 15 Jul 15 โ€“ Sep 16
Fall Sowing July 7 Jul 7 โ€“ Jul 21

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 Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Fall Sowing Harvest
August Harvest
September Harvest
October โ€”
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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 3a

๐Ÿ“† Growing Season

132 days in Cook County

Growing Tips for Cauliflower in Cook County

Direct sow Cauliflower outdoors after May 20 in Cook County when soil has warmed and frost danger has passed.

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

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 Cook County, MN?

Cook County is in Zone 3a with an average last frost of May 20. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cook County, MN?

Cook County, Minnesota is in USDA Hardiness Zone 3a. The average last spring frost is May 20 and first fall frost is September 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Cook County gardeners in Zone 3a 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 Cook County, MN. Local conditions may vary. Last updated: April 2026.