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When to Plant Squash (Winter) in USDA Zone 4b

Winter squash includes butternut, acorn, delicata, and hubbard varieties grown to full maturity with hard rinds for storage. They develop sweet, dense flesh.

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

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

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

Squash (Winter) Planting Calendar — Zone 4b

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 22 May 22 – Jun 5
Direct Sow May 15 May 15 – Jun 5
Harvest August 14 Aug 14 – Oct 9

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
August Harvest
September Harvest
October Harvest
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

Moderate — regular watering

Days to Maturity

80–120 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 Spacing30 inches apart
Row Spacing42 inches between rows

Succession Planting Squash (Winter) in Zone 4b

2
successive plantings in Zone 4b's ~155-day season

Sow every 9.1 weeks for continuous harvest throughout the season.

Growing Tips for Squash (Winter) in Zone 4b

Zone 4b has a short growing season (~155 days). Start Squash (Winter) indoors early and use season-extension techniques like row covers and cold frames.

Direct sow after last frost on rich mounds. Allow ample space for sprawling vines. Cure harvested fruits in the sun for 10 days before storing in a cool, dry place.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
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Saving Squash (Winter) Seeds

Recommended for Your Garden

💡
LED Grow Lights $25-60

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

🔥
Seedling Heat Mat $15-35

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

🪡
Floating Row Covers $12-30

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

Frequently Asked Questions

When should I plant Squash (Winter) in Zone 4b?

In Zone 4b, plan your Squash (Winter) planting around the average last frost date of May 1. Start seeds indoors around March 20. Direct sow outdoors around May 15. Transplant seedlings around May 22.

Can Squash (Winter) grow in Zone 4b?

Yes, Squash (Winter) can grow well in Zone 4b, hardy in USDA zones 3a through 11b. Zone 4b has a growing season of approximately 155 days, which is sufficient for Squash (Winter) (80-120 days to maturity).

When can I harvest Squash (Winter) in Zone 4b?

In Zone 4b, expect to harvest Squash (Winter) from August 14 – October 9. Squash (Winter) takes 80-120 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 Squash (Winter)?

Good companion plants for Squash (Winter) include Corn, Green Beans, Radish. These companions can help with pest control, pollination, and nutrient sharing.

🌱

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A 22-page printable planner tailored to Zone 4b. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

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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.