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When to Plant Petunia in Harrison County, TX

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, Texas is in USDA Zone 8b. The average last spring frost is March 13 and the first fall frost is November 14, giving you a growing season of approximately 246 days.

At an elevation of 168 feet, Harrison County receives approximately 63.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Petunia may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Petunia will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Petunia root diseases.

Annual Blooms in Summer Pollinator-friendly Fragrant
Harrison County, TX (Zone 8b) Long season
246 days
Last Spring Frost March 13
246 growing days
First Fall Frost November 14

Harrison County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Petunia Planting Timeline — Harrison County, TX

Petunia Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors March 6 Mar 6 – Mar 20
Bloom May 15 May 15 – Oct 2

· 12" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February
March Transplant Outdoors
April
May Bloom
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 8b

📆 Growing Season

246 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, TX?

Harrison County is in Zone 8b with an average last frost of March 13. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harrison County, TX?

Harrison County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 13 and first fall frost is November 14.

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Your Harrison County Garden Planner — Free

A 22-page printable planner built for Harrison County (Zone 8b). 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, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

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