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When to Plant Pumpkin in Nelson County, ND

Nelson County, North Dakota Zone 4a May

What to do in May

Your garden in Nelson County, North Dakota is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 12
Avg. first frost September 27
Soil temp (4") 49°F
Watering Low
Pest pressure Low
Daylight 15 hrs
  1. Plant pumpkin from seed, right in the garden

    Your soil is 49°F — warm enough for these to germinate without babying.

Coming up in June — start thinking about
  • Transplants going out: pumpkin
  • Starting indoors: pumpkin

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

Nelson County, North Dakota is in USDA Zone 4a. The average last spring frost is May 12 and the first fall frost is September 27, giving you a growing season of approximately 138 days.

At an elevation of 547 feet, Nelson County receives approximately 33.3 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Pumpkin to ensure they mature before fall.

Nelson County, ND (Zone 4a) Short season
138 days
Last Spring Frost May 12
138 growing days
First Fall Frost September 27
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Nelson County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 27 Transplant: May 29 🍅 Harvest: Aug 28 – Oct 16
Recommended (50%) ✗ May not fit
Start indoors: Mar 31 Transplant: Jun 2 🍅 Harvest: Sep 1 – Oct 20
Safe Start (90%) ✗ May not fit
Start indoors: Apr 11 Transplant: Jun 13 🍅 Harvest: Sep 12 – Oct 31

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.

Soil Compatibility in Nelson County

How your county's soil matches Pumpkin's growing requirements.

Soil pH

Your soil pH (6.6–7.8) overlaps with Pumpkin's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Nelson County is excellent for Pumpkin — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) — Pumpkin will thrive.

How to Plant Pumpkin

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

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
1.0″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 352 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 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 5.6" 4.6" 1" 💧 Light watering
Jun 5.6" 5.8" 0" ✅ Rainfall sufficient
Jul 5.6" 3.9" 1.7" 💧 Light watering
Aug 5.6" 4.1" 1.5" 💧 Light watering
Sep 5.6" 3.5" 2.1" 💧 Light watering
Oct 2" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Nelson County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~1,025 GDD — county provides 1,380 GDD Excellent fit

Pumpkin Planting Timeline — Nelson County, ND

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 – Apr 14
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest September 1 Sep 1 – Oct 20

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · Only during dry spells

📅 Days to Maturity

85–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

138 days in Nelson County

Growing Tips for Pumpkin in Nelson County

Direct sow Pumpkin outdoors after May 12 in Nelson County when soil has warmed and frost danger has passed.

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 Nelson County, ND?

Nelson County is in Zone 4a with an average last frost of May 12. Plan your Pumpkin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Nelson County, ND?

Nelson County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 12 and first fall frost is September 27.

🌱

Your Nelson County Garden Planner — Free

A 24-page printable planner built for Nelson County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Nelson County, ND. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.