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When to Plant Cranberries in Grand Forks County, ND

Grand Forks County, North Dakota Zone 3b April

This month in Grand Forks County, North Dakota

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

Avg. last frost May 11
Avg. first frost September 30
Soil temp (4") 37°F
Watering None
Pest pressure Low
Daylight 13.4 hrs

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Cranberries are low-growing, vine-like shrubs that produce tart red berries in fall. They grow in acidic, boggy conditions and are surprisingly easy to cultivate.

Grand Forks County, North Dakota is in USDA Zone 3b. 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 572 feet, Grand Forks County receives approximately 27.7 inches of rainfall annually with predominantly loam soil. Summer highs average 79°F, so choose short-season varieties of Cranberries to ensure they mature before fall.

Grand Forks County, ND (Zone 3b) Short season
142 days
Last Spring Frost May 11
142 growing days
First Fall Frost September 30
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Grand Forks County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Jun 1
Recommended (50%) ✓ Fits season
Transplant: Jun 8
Safe Start (90%) ✓ Fits season
Transplant: Jun 20

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 Grand Forks County

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

Soil pH

Your soil pH (6.8–7.4) is more alkaline than Cranberries prefers (4.0–5.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Grand Forks County is excellent for Cranberries — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Cranberries.

How to Plant Cranberries

36"
Between Plants
48"
Between Rows

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,032 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Cranberries

Cranberries needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Cranberries Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 6.5" 4.1" 2.4" 💧 Light watering
Jun 6.5" 4.6" 1.9" 💧 Light watering
Jul 6.5" 3" 3.5" 🚿 Regular watering
Aug 6.5" 3.6" 2.9" 💧 Light watering
Sep 6.5" 2.5" 4" 🚿 Regular watering
Oct 1.8" 0" ❄️ Dormant
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

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

Cranberries 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.

Cranberries needs ~8,441 GDD — county provides 1,313 GDD May not mature

Cranberries Planting Timeline — Grand Forks County, ND

Cranberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 8 Jun 8 – Jun 22

· 36" apart · Rows 48" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May
June Transplant Outdoors
July
August
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 4–5.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 3b

📆 Growing Season

142 days in Grand Forks County

Growing Tips for Cranberries in Grand Forks County

Direct sow Cranberries outdoors after May 11 in Grand Forks County when soil has warmed and frost danger has passed.

Your 142.0-day growing season in Grand Forks County is tight for Cranberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Create an acidic, consistently moist bed with peat moss. Cranberries do not need to be flooded to grow; flooding is only used for commercial harvesting. Mulch with sand in early spring.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cranberries in Grand Forks County, ND?

Grand Forks County is in Zone 3b with an average last frost of May 11. Plan your Cranberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grand Forks County, ND?

Grand Forks County, North Dakota is in USDA Hardiness Zone 3b. The average last spring frost is May 11 and first fall frost is September 30.

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Your Grand Forks County Garden Planner — Free

A 24-page printable planner built for Grand Forks County (Zone 3b). 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 Grand Forks County, ND. Local conditions may vary. Last updated: April 2026.

Sources & credits

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