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When to Plant Hubbard Squash in Mountrail County, ND

Mountrail County, North Dakota Zone 4a May

Your May gardening checklist

May is a pivotal month for Mountrail County, North Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 17
Avg. first frost September 22
Soil temp (4") 50°F
Watering Moderate
Pest pressure Low
Daylight 15 hrs
  1. Direct-sow hubbard squash

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

June will be here before you know it — start on
  • Transplants going out: hubbard squash
  • Starting indoors: hubbard squash

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Hubbard squash is a large, bumpy-skinned winter squash with dense, sweet, dry flesh ideal for baking and pies. The hard shell allows storage for 6 months or more.

Mountrail County, North Dakota is in USDA Zone 4a. The average last spring frost is May 17 and the first fall frost is September 22, giving you a growing season of approximately 128 days.

At an elevation of 1,059 feet, Mountrail County receives approximately 26.2 inches of rainfall annually with predominantly loam soil. Summer highs average 78°F, so choose short-season varieties of Hubbard Squash to ensure they mature before fall.

Mountrail County, ND (Zone 4a) Short season
128 days
Last Spring Frost May 17
128 growing days
First Fall Frost September 22
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Mountrail County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 31 Transplant: Jun 2 🍅 Harvest: Sep 15 – Oct 20
Recommended (50%) ✗ May not fit
Start indoors: Apr 5 Transplant: Jun 7 🍅 Harvest: Sep 20 – Oct 25
Safe Start (90%) ✗ May not fit
Start indoors: Apr 17 Transplant: Jun 19 🍅 Harvest: Oct 2 – Nov 6

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 Mountrail County

How your county's soil matches Hubbard Squash's growing requirements.

Soil pH

Your soil pH (6.8–7.5) is more alkaline than Hubbard Squash prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Mountrail County is excellent for Hubbard Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

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

How to Plant Hubbard Squash

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

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 192 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Hubbard Squash

Hubbard Squash needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Hubbard Squash Needs Rainfall You Supplement Action
Jan 2" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 3" 0" ❄️ Dormant
May 4.3" 2.9" 1.4" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 2.1" 2.2" 🚿 Regular watering
Aug 4.3" 2.7" 1.6" 💧 Light watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 2.5" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Mountrail County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Hubbard Squash 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.

Hubbard Squash needs ~935 GDD — county provides 1,088 GDD Good fit

Hubbard Squash Planting Timeline — Mountrail County, ND

Hubbard Squash Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors June 7 Jun 7 – Jun 21
Direct Sow May 31 May 31 – Jun 21
Harvest September 20 Sep 20 – Oct 25

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

Month-by-Month Timeline

MonthActivities
January
February
March
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"/week · Only during dry spells

📅 Days to Maturity

100–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4a

📆 Growing Season

128 days in Mountrail County

Growing Tips for Hubbard Squash in Mountrail County

Direct sow Hubbard Squash outdoors after May 17 in Mountrail County when soil has warmed and frost danger has passed.

Your 128.0-day growing season in Mountrail County is tight for Hubbard Squash (100.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.

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

General growing tips

Start seeds indoors in short-season areas. Requires ample space and rich soil. Harvest when the skin is very hard and the color is deep. Cure in the sun before storing.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hubbard Squash in Mountrail County, ND?

Mountrail County is in Zone 4a with an average last frost of May 17. Plan your Hubbard Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mountrail County, ND?

Mountrail County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 17 and first fall frost is September 22.

🌱

Your Mountrail County Garden Planner — Free

A 24-page printable planner built for Mountrail 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 Mountrail 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.