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When to Plant Petunia in Wilson County, TX

Wilson County, Texas Zone 9a June

Your June game plan for Wilson County, Texas

Here's what deserves your attention in Wilson County, Texas this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost March 4
Avg. first frost November 25
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.9 hrs
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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.

Wilson County, Texas is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 25, giving you a growing season of approximately 266 days.

At an elevation of 2,660 feet, Wilson County receives approximately 62.3 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Petunia during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Petunia root diseases.

Annual Blooms in Summer Pollinator-friendly Fragrant
Wilson County, TX (Zone 9a) Long season
266 days
Last Spring Frost March 4
266 growing days
First Fall Frost November 25

Wilson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Petunia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Start indoors: Dec 26 Transplant: Feb 6 🌸 Bloom: Apr 17 – Sep 18
Recommended (50%) ✓ Fits season (56 days to spare)
Start indoors: Jan 7 Transplant: Feb 18 🌸 Bloom: Apr 29 – Sep 30
Safe Start (90%) ✓ Fits season (47 days to spare)
Start indoors: Feb 2 Transplant: Mar 16 🌸 Bloom: May 25 – Oct 26

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 Wilson County

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

Soil pH

Your soil pH (6.5–7.4) overlaps with Petunia's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in Wilson County is excellent for Petunia — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Petunia.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Petunia.

How to Plant Petunia

12"
Between Plants
12"
Between Rows

Succession Planting Petunia

4
successive plantings in your 266-day season

Sow every 8 weeks. Last sowing by Aug 27 to harvest before frost.

Petunia Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 899 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Petunia

Petunia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Petunia Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 4.3" 4.2" 0.1" 💧 Light watering
Apr 4.3" 5.6" 0" ✅ Rainfall sufficient
May 4.3" 9.2" 0" ✅ Rainfall sufficient
Jun 4.3" 10.7" 0" ✅ Rainfall sufficient
Jul 4.3" 8.7" 0" ✅ Rainfall sufficient
Aug 4.3" 7.7" 0" ✅ Rainfall sufficient
Sep 4.3" 5.1" 0" ✅ Rainfall sufficient
Oct 4.3" 3.9" 0.4" 💧 Light watering
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 1.7" 0" ❄️ Dormant

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

Petunia 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.

Petunia needs ~1,580 GDD — county provides 5,253 GDD Excellent fit

Petunia Planting Timeline — Wilson County, TX

Petunia Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 – Jan 21
Transplant Outdoors February 18 Feb 18 – Mar 4
Bloom April 29 Apr 29 – Sep 30

· 12" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

266 days in Wilson County

Growing Tips for Petunia in Wilson County

Direct sow Petunia outdoors after March 04 in Wilson County when soil has warmed and frost danger has passed.

Common pests for Petunia in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Wilson County, TX?

Wilson County is in Zone 9a with an average last frost of March 4. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wilson County, TX?

Wilson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 25.

🌱

Your Wilson County Garden Planner — Free

A 22-page printable planner built for Wilson County (Zone 9a). 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 Wilson County, TX. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.