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When to Plant Pumpkin in St. Louis City, MO

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

St. Louis City, Missouri is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 27, giving you a growing season of approximately 202 days.

At an elevation of 612 feet, St. Louis City receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Pumpkin during the growing season.

St. Louis City, MO (Zone 6b) Long season
202 days
Last Spring Frost April 8
202 growing days
First Fall Frost October 27

St. Louis City Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Feb 24 Transplant: Apr 14 🍅 Harvest: Jul 14 – Sep 1
Recommended (50%) ✓ Fits season (48 days to spare)
Start indoors: Mar 4 Transplant: Apr 22 🍅 Harvest: Jul 22 – Sep 9
Safe Start (90%) ✓ Fits season (53 days to spare)
Start indoors: Mar 16 Transplant: May 4 🍅 Harvest: Aug 3 – Sep 21

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
0.2″/week
Watering frequency Only during dry spells
Season total 327 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Pumpkin needs ~1,871 GDD — county provides 3,686 GDD Excellent fit

Pumpkin Planting Timeline โ€” St. Louis City, MO

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 โ€“ Mar 18
Transplant Outdoors April 22 Apr 22 โ€“ May 6
Direct Sow April 15 Apr 15 โ€“ May 6
Harvest July 22 Jul 22 โ€“ Sep 9

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

85โ€“120 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

202 days

Growing Tips for St. Louis City

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 St. Louis City, MO?

St. Louis City is in Zone 6b with an average last frost of April 8. Plan your Pumpkin planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is St. Louis City, MO?

St. Louis City, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

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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 St. Louis City, MO. Local conditions may vary. Last updated: April 2026.