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When to Plant Squash (Winter) in Peterborough, ON

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

Peterborough, Ontario is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 17, giving you a growing season of approximately 187 days.

At an elevation of 656 feet, Peterborough receives approximately 40.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Squash (Winter) to ensure they mature before fall. Clay soil retains moisture well for Squash (Winter), but amend with compost to improve drainage and prevent root rot.

Peterborough, ON (Zone 6b) Moderate season
187 days
Last Spring Frost April 13
187 growing days
First Fall Frost October 17

Peterborough Soil Profile

Soil Type

Clay Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (29 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🍅 Harvest: Jul 22 – Sep 16
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🍅 Harvest: Jul 22 – Sep 16
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🍅 Harvest: Jul 22 – Sep 16

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 147 gal / 100 sq ft
Squash (Winter) needs ~1,075 GDD — county provides 2,010 GDD Excellent fit

Squash (Winter) Planting Timeline โ€” Peterborough, ON

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 โ€“ Mar 23
Transplant Outdoors April 27 Apr 27 โ€“ May 11
Direct Sow April 20 Apr 20 โ€“ May 11
Harvest July 20 Jul 20 โ€“ Sep 14

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

80โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6b

Growing Season

187 days

Growing Tips for Peterborough

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Squash (Winter) in Peterborough, ON?

Peterborough is in Zone 6b with an average last frost of April 13. Plan your Squash (Winter) planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Peterborough, ON?

Peterborough, Ontario is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 17.

๐ŸŒฑ

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Peterborough, ON. Local conditions may vary. Last updated: April 2026.