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When to Plant Cauliflower in USDA Zone 5a

Cauliflower
Zone 5a Zone 5a June

June to-do list for Zone 5a

We've pulled the most time-sensitive tasks for Zone 5a this June and put them front and centre. Tackle them in order.

Avg. last frost May 6
Avg. first frost October 6
  1. Start cauliflower under lights

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

Coming up in July — start thinking about
  • First harvests: cauliflower
  • Fall sowing: cauliflower
Get the full Zone 5a 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 5a, the average last spring frost is around April 25 and the first fall frost is around October 8, giving you a growing season of approximately 166 days.

Zone 5a Moderate season
166 days
Last Spring Frost April 25
166 growing days
First Fall Frost October 8

Cauliflower Planting Timeline — Zone 5a

Where Is USDA Zone 5a?

The map below highlights the states that contain Zone 5a. 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 5a

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 11 Apr 11 – May 2
Harvest June 20 Jun 20 – Aug 22
Fall Sowing July 30 Jul 30 – Aug 13

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

Month-by-Month Timeline

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

Free Zone 5a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 5a with start dates, transplant windows, and harvest times.

Instant PDF download. No spam, unsubscribe any time.

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

-20°F to -15°F average annual minimum

Growing Season

166 days (Zone 5a average)

Planting Specifications

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

Succession Planting Cauliflower in Zone 5a

3
successive plantings in Zone 5a's ~166-day season

Sow every 6.3 weeks for continuous harvest throughout the season.

Growing Tips for Cauliflower in Zone 5a

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 5a?

In Zone 5a, plan your Cauliflower planting around the average last frost date of April 25. Start seeds indoors around March 21. Direct sow outdoors around April 11. Transplant seedlings around April 25.

Can Cauliflower grow in Zone 5a?

Yes, Cauliflower can grow well in Zone 5a, hardy in USDA zones 2a through 10b. Zone 5a has a growing season of approximately 166 days, which is sufficient for Cauliflower (55-100 days to maturity).

When can I harvest Cauliflower in Zone 5a?

In Zone 5a, expect to harvest Cauliflower from June 20 – August 22. Cauliflower takes 55-100 days from planting to harvest.

What is the last frost date for Zone 5a?

The average last spring frost in Zone 5a is around April 25, and the first fall frost is around October 8. This gives a growing season of approximately 166 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 Zone 5a Garden Planner — Free

A 22-page printable planner tailored to Zone 5a. 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: June 2026.

Sources & credits

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