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When to Plant Blueberries in Union County, TN

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.

Union County, Tennessee is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 29, giving you a growing season of approximately 202 days.

At an elevation of 1,122 feet, Union County receives approximately 50.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Blueberries during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Blueberries root diseases.

Union County, TN (Zone 7a) Long season
202 days
Last Spring Frost April 10
202 growing days
First Fall Frost October 29

Union County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 25
Recommended (50%) ✓ Fits season
Transplant: May 1
Safe Start (90%) ✓ Fits season
Transplant: May 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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Blueberries needs ~14,600 GDD — county provides 3,232 GDD May not mature

Blueberries Planting Timeline โ€” Union County, TN

Blueberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 1 May 1 โ€“ May 15

ยท 48" apart ยท Rows 72" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Transplant Outdoors
June โ€”
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 7a

Growing Season

202 days

Growing Tips for Union 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 Union County, TN?

Union County is in Zone 7a with an average last frost of April 10. Plan your Blueberries planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Union County, TN?

Union County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Union County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

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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 Union County, TN. Local conditions may vary. Last updated: April 2026.