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When to plant Petunia in Phillips County, AR

Phillips County's 243-day season only supports one Petunia planting per year. Sow between March 14 and March 28 for the best chance at full maturity before November 12.

When to Plant Petunia in Phillips County, AR

Phillips County, Arkansas Zone 8a July

July in the garden — Phillips County, Arkansas

July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Phillips County, Arkansas.

Avg. last frost March 14
Avg. first frost November 12
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Collect petunia at their peak

    If you can't use it all right away, check the food-preservation section of your planner.

Coming up in August — start thinking about
  • First harvests: petunia

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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.

Phillips County, Arkansas is in USDA Zone 8a. The average last spring frost is March 14 and the first fall frost is November 12, giving you a growing season of approximately 243 days.

At an elevation of 678 feet, Phillips County receives approximately 50 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Petunia during the growing season.

Annual Blooms in Summer Pollinator-friendly Fragrant
Phillips County, AR (Zone 8a) Long season
243 days
Last Spring Frost March 14
243 growing days
First Fall Frost November 12

Phillips County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Petunia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Jan 12 Transplant: Mar 9 🌸 Bloom: May 18 – Sep 21
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Jan 17 Transplant: Mar 14 🌸 Bloom: May 23 – Sep 26
Safe Start (90%) ✓ Fits season (40 days to spare)
Start indoors: Feb 10 Transplant: Apr 7 🌸 Bloom: Jun 16 – Oct 20

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 Phillips County

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

Soil pH

Your soil pH (5.6–6.7) overlaps with Petunia's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.8%). Annual compost additions will help Petunia.

How to Plant Petunia

12"
Between Plants
12"
Between Rows

Succession Planting Petunia

4
successive plantings in your 243-day season

Sow every 8 weeks. Last sowing by Aug 14 to harvest before frost.

Petunia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 352 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 4.4" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4.3" 5.5" 0" ✅ Rainfall sufficient
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 5.2" 0" ✅ Rainfall sufficient
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 4.3" 3.6" 0.7" 💧 Light watering
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Phillips 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 4,799 GDD Excellent fit

Petunia Planting Timeline — Phillips County, AR

Petunia Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors March 14 Mar 14 – Mar 28
Bloom May 23 May 23 – Sep 26

· 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
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

243 days in Phillips County

Growing Tips for Petunia in Phillips County

Direct sow Petunia outdoors after March 14 in Phillips 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 Phillips County, AR?

Phillips County is in Zone 8a with an average last frost of March 14. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Phillips County, AR?

Phillips County, Arkansas is in USDA Hardiness Zone 8a. The average last spring frost is March 14 and first fall frost is November 12.

When should I plant Petunia in Phillips County, AR?

In Phillips County, AR, plant Petunia after the last frost (around March 14) and before the first frost (around November 12). Best results when soil holds above 50°F.

What growing zone is Phillips County, AR for Petunia?

Phillips County sits in USDA Zone 8a. Petunia grows reliably in zones 2a through 11b, so it's a good fit here.

Can Petunia grow in Phillips County's climate?

Yes — Petunia grows well in Phillips County's temperate climate. Phillips County averages a 243-day frost-free season, with last frost around March 14 and first frost around November 12.

🌱

Your Phillips County Garden Planner — Free

A 22-page printable planner built for Phillips County (Zone 8a). 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 Phillips County, AR. Local conditions may vary. Last updated: July 2026.

Sources & credits

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