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When to Plant Pumpkin in Griggs County, ND

Griggs County, North Dakota Zone 4a May

Griggs County, North Dakota gardeners: here's your May plan

A quick May briefing for Griggs County, North Dakota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 11
Avg. first frost September 30
Soil temp (4") 53°F
Watering Moderate
Pest pressure Low
Daylight 14.9 hrs
  1. Seed pumpkin outdoors

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Looking ahead to June
  • 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.

Griggs County, North Dakota is in USDA Zone 4a. The average last spring frost is May 11 and the first fall frost is September 30, giving you a growing season of approximately 142 days.

At an elevation of 660 feet, Griggs County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Pumpkin to ensure they mature before fall.

Griggs County, ND (Zone 4a) Short season
142 days
Last Spring Frost May 11
142 growing days
First Fall Frost September 30
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Griggs County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 21 Transplant: May 23 🍅 Harvest: Aug 22 – Oct 10
Recommended (50%) ✗ May not fit
Start indoors: Mar 30 Transplant: Jun 1 🍅 Harvest: Aug 31 – Oct 19
Safe Start (90%) ✗ May not fit
Start indoors: Apr 10 Transplant: Jun 12 🍅 Harvest: Sep 11 – Oct 30

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 Griggs County

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

Soil pH

Your soil pH (6.7–7.8) overlaps with Pumpkin's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Pumpkin.

How to Plant Pumpkin

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

Plant Water Budget

Plant needs
1.3″/week
Rainfall provides
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,012 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 0.6" 0" ❄️ Dormant
Feb 0.7" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 5.6" 3" 2.6" 💧 Light watering
Jun 5.6" 3.5" 2.1" 💧 Light watering
Jul 5.6" 2.7" 2.9" 🚿 Regular watering
Aug 5.6" 2.4" 3.2" 🚿 Regular watering
Sep 5.6" 2" 3.6" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 0.7" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Griggs 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 ~1,102 GDD — county provides 1,526 GDD Excellent fit

Pumpkin Planting Timeline — Griggs County, ND

Pumpkin Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 – Apr 13
Transplant Outdoors June 1 Jun 1 – Jun 15
Direct Sow May 25 May 25 – Jun 15
Harvest August 31 Aug 31 – Oct 19

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 Harvest
September Harvest
October Harvest
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.3"/week · 2-3 times/week

📅 Days to Maturity

85–120 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

142 days in Griggs County

Growing Tips for Pumpkin in Griggs County

Direct sow Pumpkin outdoors after May 11 in Griggs 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.

Griggs County receives only 21" of rain annually. Pumpkin needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Griggs County, ND?

Griggs County is in Zone 4a with an average last frost of May 11. Plan your Pumpkin planting based on this frost date — see the calendar above for exact timing.

What planting zone is Griggs County, ND?

Griggs County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 11 and first fall frost is September 30.

🌱

Your Griggs County Garden Planner — Free

A 24-page printable planner built for Griggs 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 Griggs 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.