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When to Plant Cauliflower in USDA Zone 3b

Zone 3b Zone 3b April

Zone 3b gardeners: here's your April plan

Your garden in Zone 3b is working on a schedule, even when you're not. Here's where you should be this April.

Avg. last frost May 14
Avg. first frost September 27
May will be here before you know it — start on
  • Transplants going out: cauliflower
  • Direct-sowing: cauliflower
Get the full Zone 3b Garden Planner — free →
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.

In Zone 3b, the average last spring frost is around May 10 and the first fall frost is around September 22, giving you a growing season of approximately 135 days.

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Zone 3b Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Cauliflower Planting Timeline — Zone 3b

Where Is USDA Zone 3b?

The map below highlights the states that contain Zone 3b. 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 3b

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 10 May 10 – May 24
Direct Sow May 3 May 3 – May 24
Harvest July 5 Jul 5 – Sep 6
Fall Sowing June 30 Jun 30 – Jul 14

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

Month-by-Month Timeline

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

Free Zone 3b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 3b 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

°F to °F average annual minimum

Growing Season

135 days (Zone average)

Planting Specifications

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

Succession Planting Cauliflower in Zone

2
successive plantings in Zone 's ~135-day season

Sow every 6.3 weeks for continuous harvest throughout the season.

Growing Tips for Cauliflower in Zone

Zone has a short growing season (~135 days). Start Cauliflower indoors early and use season-extension techniques like row covers and cold frames.

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
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Saving Cauliflower Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

🏷️
Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Related Plants

Frequently Asked Questions

When should I plant Cauliflower in Zone 3b?

In Zone 3b, plan your Cauliflower planting around the average last frost date of May 10. Start seeds indoors around March 29. Direct sow outdoors around May 3. Transplant seedlings around May 10.

Can Cauliflower grow in Zone 3b?

Yes, Cauliflower can grow well in Zone 3b, hardy in USDA zones 2a through 10b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Cauliflower (55-100 days to maturity).

When can I harvest Cauliflower in Zone 3b?

In Zone 3b, expect to harvest Cauliflower from July 5 – September 6. Cauliflower takes 55-100 days from planting to harvest.

What is the last frost date for Zone 3b?

The average last spring frost in Zone 3b is around May 10, and the first fall frost is around September 22. This gives a growing season of approximately 135 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.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

Instant PDF download. No spam, unsubscribe any time.

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.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.