Blog

When to Plant Pumpkin in Webster County, IA

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

Webster County, Iowa is in USDA Zone 4b. The average last spring frost is April 28 and the first fall frost is October 6, giving you a growing season of approximately 161 days.

At an elevation of 1,065 feet, Webster County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Pumpkin to ensure they mature before fall.

Webster County, IA (Zone 4b) Moderate season
161 days
Last Spring Frost April 28
161 growing days
First Fall Frost October 6

Webster County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (0 days to spare)
Start indoors: Mar 11 Transplant: May 13 🍅 Harvest: Aug 12 – Sep 30
Recommended (50%) ✓ Fits season (0 days to spare)
Start indoors: Mar 17 Transplant: May 19 🍅 Harvest: Aug 18 – Oct 6
Safe Start (90%) ✗ May not fit
Start indoors: Apr 2 Transplant: Jun 4 🍅 Harvest: Sep 3 – Oct 22

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
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 734 gal / 100 sq ft
Pumpkin needs ~1,025 GDD — county provides 1,610 GDD Excellent fit

Pumpkin Planting Timeline โ€” Webster County, IA

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 โ€“ Mar 31
Transplant Outdoors May 19 May 19 โ€“ Jun 2
Direct Sow May 12 May 12 โ€“ Jun 2
Harvest August 18 Aug 18 โ€“ Oct 6

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

85โ€“120 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 4b

Growing Season

161 days

Growing Tips for Webster County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Pumpkin in Webster County, IA?

Webster County is in Zone 4b with an average last frost of April 28. Plan your Pumpkin planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Webster County, IA?

Webster County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 28 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Webster County gardeners in Zone 4b 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 Webster County, IA. Local conditions may vary. Last updated: April 2026.