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When to Plant Cauliflower in Carlton 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.

Carlton County, Minnesota is in USDA Zone 3b. The average last spring frost is May 12 and the first fall frost is October 2, giving you a growing season of approximately 143 days.

At an elevation of 516 feet, Carlton County receives approximately 32.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Cauliflower to ensure they mature before fall.

Carlton County, MN (Zone 3b) Short season
143 days
Last Spring Frost May 12
143 growing days
First Fall Frost October 2

Carlton County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (23 days to spare)
Start indoors: Mar 24 Transplant: May 5 🍅 Harvest: Jun 30 – Sep 1
Recommended (50%) ✓ Fits season (24 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 8
Safe Start (90%) ✓ Fits season (19 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 Carlton County

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

Soil pH

Your soil pH (6.2โ€“7.1) overlaps with Cauliflower's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) 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

3
successive plantings in your 143-day season

Sow every 6.3 weeks. Last sowing by Jun 24 to harvest before frost.

For a dedicated fall crop, sow by Jul 10.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 56 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€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.5" 0" โ„๏ธ Dormant
Mar โ€” 2.5" 0" โ„๏ธ Dormant
Apr โ€” 3.1" 0" โ„๏ธ Dormant
May 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Jun 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jul 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Aug 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Sep 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Oct 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Nov โ€” 2.5" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Carlton 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 ~891 GDD — county provides 1,644 GDD Excellent fit

Cauliflower Planting Timeline โ€” Carlton County, MN

Cauliflower Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 โ€“ Apr 14
Transplant Outdoors May 12 May 12 โ€“ May 26
Direct Sow May 5 May 5 โ€“ May 26
Harvest July 7 Jul 7 โ€“ Sep 8
Fall Sowing July 10 Jul 10 โ€“ Jul 24

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June โ€”
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 Only during dry spells

๐Ÿ“… Days to Maturity

55โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 3b

๐Ÿ“† Growing Season

143 days in Carlton County

Growing Tips for Cauliflower in Carlton County

Direct sow Cauliflower outdoors after May 12 in Carlton 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 Carlton County, MN?

Carlton County is in Zone 3b with an average last frost of May 12. Plan your Cauliflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Carlton County, MN?

Carlton County, Minnesota is in USDA Hardiness Zone 3b. The average last spring frost is May 12 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

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