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When to plant Petunia in Harrison County, IN

Plant Petunia in Harrison County during the brief April 15–April 29 window. With 206 frost-free days, fall plantings can't mature before October 31.

When to Plant Petunia in Harrison County, IN

Petunias (Petunia x hybrida) are warm-season tender annuals prized for their prolific, trumpet-shaped blooms in nearly every color. They perform from hanging baskets to garden borders and bloom continuously from late spring until frost, provided spent flowers are removed regularly.

Harrison County, Indiana is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 31, giving you a growing season of approximately 206 days.

At an elevation of 528 feet, Harrison County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Petunia during the growing season.

Annual Blooms in Summer Pollinator-friendly Fragrant
Harrison County, IN (Zone 6b) Long season
206 days
Last Spring Frost April 8
206 growing days
First Fall Frost October 31

Harrison County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Petunia Planting Timeline — Harrison County, IN

Petunia Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Bloom June 24 Jun 24 – Oct 7

· 12" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

206 days in Harrison County

Growing Tips for Harrison County

Start seeds indoors 8–10 weeks before last frost; seeds need light to germinate — press onto moist mix surface, do not cover. Transplant after last frost once nights stay above 50°F. Pinch back leggy plants mid-summer to encourage bushy re-bloom. Wave/spreading types tolerate light shade but bloom less. Feed every 2 weeks with balanced fertilizer once established.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Petunia in Harrison County, IN?

Harrison County is in Zone 6b with an average last frost of April 8. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harrison County, IN?

Harrison County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 31.

When should I plant Petunia in Harrison County, IN?

In Harrison County, IN, plant Petunia after the last frost (around April 8) and before the first frost (around October 31). Best results when soil holds above 50°F.

What growing zone is Harrison County, IN for Petunia?

Harrison County sits in USDA Zone 6b. Petunia grows reliably in zones 2a through 11b, so it's a good fit here.

Can Petunia grow in Harrison County's climate?

Yes — Petunia grows well in Harrison County's temperate climate. Harrison County averages a 206-day frost-free season, with last frost around April 8 and first frost around October 31.

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Your Harrison County Garden Planner — Free

A 22-page printable planner built for Harrison 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.

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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 Harrison County, IN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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