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When to Plant Squash (Summer) in USDA Zone 3b

Zone 3b Zone 3b April

Zone 3b gardeners: here's your April plan

A quick April briefing for Zone 3b gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 14
Avg. first frost September 27
A few tasks this April that'll pay off in May
  • Direct-sowing: squash (summer)
Send me my free Zone 3b Planting Guide →

Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

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

Squash (Summer) 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 Squash (Summer) planting schedule for that location.

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

Squash (Summer) Planting Calendar — Zone 3b

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest July 19 Jul 19 – Sep 20

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July 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

Moderate — regular watering

Days to Maturity

45–65 days

Soil pH

6 – 7.5

Zone Temperature Range

°F to °F average annual minimum

Growing Season

135 days (Zone average)

Planting Specifications

Planting Depth1 inches
Plant Spacing30 inches apart
Row Spacing42 inches between rows

Succession Planting Squash (Summer) in Zone

3
successive plantings in Zone 's ~135-day season

Sow every 5.1 weeks for continuous harvest throughout the season.

Growing Tips for Squash (Summer) in Zone

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

Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
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Saving Squash (Summer) 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 Squash (Summer) in Zone 3b?

In Zone 3b, plan your Squash (Summer) planting around the average last frost date of May 10. Start seeds indoors around March 29. Direct sow outdoors around May 24. Transplant seedlings around May 31.

Can Squash (Summer) grow in Zone 3b?

Yes, Squash (Summer) can grow well in Zone 3b, hardy in USDA zones 3a through 11b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Squash (Summer) (45-65 days to maturity).

When can I harvest Squash (Summer) in Zone 3b?

In Zone 3b, expect to harvest Squash (Summer) from July 19 – September 20. Squash (Summer) takes 45-65 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 Squash (Summer)?

Good companion plants for Squash (Summer) include Corn, Green Beans, Radish, Borage. 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.