Blog

When to Plant Pumpkin in Stormont-Dundas, ON

Pumpkins are large-fruited squash varieties grown for eating, decoration, and seed production. They require ample space and a long, warm growing season.

Stormont-Dundas, Ontario is in USDA Zone 6a. The average last spring frost is April 20 and the first fall frost is October 17, giving you a growing season of approximately 180 days.

At an elevation of 196 feet, Stormont-Dundas receives approximately 35.5 inches of rainfall annually with predominantly clay loam soil. Summer highs average 79ยฐF, so choose short-season varieties of Pumpkin to ensure they mature before fall. Clay soil retains moisture well for Pumpkin, but amend with compost to improve drainage and prevent root rot.

Stormont-Dundas, ON (Zone 6a) Moderate season
180 days
Last Spring Frost April 20
180 growing days
First Fall Frost October 17

Stormont-Dundas 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 29 – Sep 16
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🍅 Harvest: Jul 29 – Sep 16
Safe Start (90%) ✓ Fits season (29 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🍅 Harvest: Jul 29 – 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.

How to Plant Pumpkin

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 756 gal / 100 sq ft

Monthly Watering Guide for Pumpkin

Pumpkin needs approximately 1.3 inches of water per week (5.6" per month). Here's how your county's rainfall compares month by month.

Month Pumpkin Needs Rainfall You Supplement Action
Jan โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.1" 0" โ„๏ธ Dormant
Apr 5.6" 3.4" 2.2" ๐Ÿ’ง Light watering
May 5.6" 3.7" 1.9" ๐Ÿ’ง Light watering
Jun 5.6" 3.9" 1.7" ๐Ÿ’ง Light watering
Jul 5.6" 4.5" 1.1" ๐Ÿ’ง Light watering
Aug 5.6" 4.1" 1.5" ๐Ÿ’ง Light watering
Sep 5.6" 2.9" 2.7" ๐Ÿ’ง Light watering
Oct 5.6" 2.8" 2.8" ๐Ÿšฟ Regular watering
Nov โ€” 2.7" 0" โ„๏ธ Dormant
Dec โ€” 2.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Stormont-Dundas). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Pumpkin Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Pumpkin needs ~948 GDD — county provides 1,665 GDD Excellent fit

Pumpkin Planting Timeline โ€” Stormont-Dundas, ON

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 โ€“ Mar 30
Transplant Outdoors May 4 May 4 โ€“ May 18
Direct Sow April 27 Apr 27 โ€“ May 18
Harvest August 3 Aug 3 โ€“ Sep 21

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.3"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

85โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

180 days in Stormont-Dundas

Growing Tips for Pumpkin in Stormont-Dundas

Common pests for Pumpkin in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow on mounds after last frost. Allow 6-10 feet between plants. Slip a board under developing fruit to prevent rot. Harvest when rind is hard and deep in color.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Pumpkin in Stormont-Dundas, ON?

Stormont-Dundas is in Zone 6a with an average last frost of April 20. Plan your Pumpkin planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Stormont-Dundas, ON?

Stormont-Dundas, Ontario is in USDA Hardiness Zone 6a. The average last spring frost is April 20 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Stormont-Dundas gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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