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When to Plant Blueberries in Foster County, ND

Blueberries are long-lived shrubs producing sweet, antioxidant-rich berries. They require acidic soil and are attractive ornamental plants with fall color and spring flowers.

Foster County, North Dakota is in USDA Zone 3b. The average last spring frost is May 10 and the first fall frost is September 30, giving you a growing season of approximately 143 days.

At an elevation of 895 feet, Foster County receives approximately 27.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Blueberries to ensure they mature before fall.

Foster County, ND (Zone 3b) Short season
143 days
Last Spring Frost May 10
143 growing days
First Fall Frost September 30

Foster County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: May 29
Recommended (50%) ✓ Fits season
Transplant: Jun 7
Safe Start (90%) ✓ Fits season
Transplant: Jun 16

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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 285 gal / 100 sq ft
Drought risk

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

Blueberries needs ~9,809 GDD — county provides 1,537 GDD May not mature

Blueberries Planting Timeline โ€” Foster County, ND

Blueberries Planting Calendar

Activity When Date Range
Transplant Outdoors June 7 Jun 7 โ€“ Jun 21

ยท 48" apart ยท Rows 72" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May โ€”
June Transplant Outdoors
July โ€”
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

730โ€“1095 days

Soil pH

4.5 โ€“ 5.5

USDA Zone

Zone 3b

Growing Season

143 days

Growing Tips for Foster County

Plant at least two varieties for cross-pollination. Acidify soil with sulfur or pine needle mulch to maintain pH 4.5-5.5. Protect ripening berries from birds with netting.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Blueberries in Foster County, ND?

Foster County is in Zone 3b with an average last frost of May 10. Plan your Blueberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Foster County, ND?

Foster County, North Dakota is in USDA Hardiness Zone 3b. The average last spring frost is May 10 and first fall frost is September 30.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Foster County gardeners in Zone 3b organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Foster County, ND. Local conditions may vary. Last updated: April 2026.