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When to Plant Cauliflower in USDA Zone 4b

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.

In Zone 4b, the average last spring frost is around May 1 and the first fall frost is around October 3, giving you a growing season of approximately 155 days.

Zone 4b Moderate season
155 days
Last Spring Frost May 1
155 growing days
First Fall Frost October 3

Cauliflower Planting Timeline — Zone 4b

Where Is USDA Zone 4b?

The map below highlights the states that contain Zone 4b. Click any state to see the Cauliflower planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Cauliflower Planting Calendar — Zone 4b

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Fall Sowing July 11 Jul 11 – Jul 25
Harvest June 26 Jun 26 – Aug 28

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

Month-by-Month Timeline

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

Free Zone 4b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 4b with start dates, transplant windows, and harvest times.

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Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

High — keep soil consistently moist

Days to Maturity

55–100 days

Soil pH

6 – 7

Zone Temperature Range

-25°F to -20°F average annual minimum

Growing Season

155 days (Zone 4b average)

Planting Specifications

Planting Depth1 inches
Plant Spacing15 inches apart
Row Spacing24 inches between rows

Growing Tips for Zone 4b

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

Level Up Your Garden

Saving Cauliflower Seeds

Recommended for Your Garden

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LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

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Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

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Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

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Frequently Asked Questions

When should I plant Cauliflower in Zone 4b?

In Zone 4b, plan your Cauliflower planting around the average last frost date of May 1. Start seeds indoors around March 20. Direct sow outdoors around April 24. Transplant seedlings around May 1.

Can Cauliflower grow in Zone 4b?

Yes, Cauliflower can grow well in Zone 4b, hardy in USDA zones 2a through 10b. Zone 4b has a growing season of approximately 155 days, which is sufficient for Cauliflower (55-100 days to maturity).

When can I harvest Cauliflower in Zone 4b?

In Zone 4b, expect to harvest Cauliflower from June 26 – August 28. Cauliflower takes 55-100 days from planting to harvest.

What is the last frost date for Zone 4b?

The average last spring frost in Zone 4b is around May 1, and the first fall frost is around October 3. This gives a growing season of approximately 155 days. These are 50% probability dates — actual frost dates vary year to year.

What should I plant next to Cauliflower?

Good companion plants for Cauliflower include Celery, Spinach, Peas. These companions can help with pest control, pollination, and nutrient sharing.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 4b, track your crops, and plan your garden season from seed to harvest.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: April 2026.