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When to Plant Blueberries in Jefferson County, IN

Jefferson County, Indiana Zone 6b May

Top priorities for Jefferson County, Indiana gardeners in May

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 10
Avg. first frost October 21
Soil temp (4") 65°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Set out blueberries seedlings

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

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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.

Jefferson County, Indiana is in USDA Zone 6b. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.

At an elevation of 1,010 feet, Jefferson County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Blueberries during the growing season.

Jefferson County, IN (Zone 6b) Moderate season
194 days
Last Spring Frost April 10
194 growing days
First Fall Frost October 21

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 27
Recommended (50%) ✓ Fits season
Transplant: May 1
Safe Start (90%) ✓ Fits season
Transplant: May 19

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 Jefferson County

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

Soil pH

Your soil pH (5.9–7.0) is more alkaline than Blueberries prefers (4.5–5.5). Add sulfur or peat moss to lower pH.

Soil Texture

The silt loam soil in Jefferson County is excellent for Blueberries — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.0%) — Blueberries will thrive.

How to Plant Blueberries

48"
Between Plants
72"
Between Rows

How Much Blueberries to Grow

5-10 lbs
Average yield per plant
2
Plants per person
48 sq ft
Space per person

For a family of 4, plant approximately 8 blueberries plants in about 192 sq ft. In Jefferson County's 194-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.7″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 838 gal / 100 sq ft

Monthly Watering Guide for Blueberries

Blueberries needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Blueberries Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 5.2" 3.1" 2.1" 💧 Light watering
May 5.2" 4.3" 0.9" 💧 Light watering
Jun 5.2" 4.3" 0.9" 💧 Light watering
Jul 5.2" 3.2" 2" 💧 Light watering
Aug 5.2" 3.8" 1.4" 💧 Light watering
Sep 5.2" 2.8" 2.4" 💧 Light watering
Oct 5.2" 2.2" 3" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Blueberries 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.

Blueberries needs ~15,969 GDD — county provides 3,395 GDD May not mature

Blueberries Planting Timeline — Jefferson County, IN

Blueberries Planting Calendar

Activity When Date Range
Transplant Outdoors May 1 May 1 – May 15

· 48" apart · Rows 72" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 1-2 times/week

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 4.5–5.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

194 days in Jefferson County

Growing Tips for Blueberries in Jefferson County

Direct sow Blueberries outdoors after April 10 in Jefferson County when soil has warmed and frost danger has passed.

Your 194.0-day growing season in Jefferson County is tight for Blueberries (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Blueberries in Jefferson County, IN?

Jefferson County is in Zone 6b with an average last frost of April 10. Plan your Blueberries planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, IN?

Jefferson County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 10 and first fall frost is October 21.

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Your Jefferson County Garden Planner — Free

A 24-page printable planner built for Jefferson County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jefferson County, IN. 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.