Blog

When to Plant Petunia in Pittsburg County, OK

Pittsburg County, Oklahoma Zone 7b July

This month in Pittsburg County, Oklahoma

Your garden in Pittsburg County, Oklahoma is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost April 4
Avg. first frost November 1
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Harvest petunia as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

To set up a strong August, finish these tasks
  • First harvests: petunia

Instant PDF download. No spam, unsubscribe any time.

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.

Pittsburg County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is November 1, giving you a growing season of approximately 211 days.

At an elevation of 620 feet, Pittsburg County receives approximately 32.6 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Petunia during the growing season.

Annual Blooms in Summer Pollinator-friendly Fragrant
Pittsburg County, OK (Zone 7b) Long season
211 days
Last Spring Frost April 4
211 growing days
First Fall Frost November 1

Pittsburg County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.2

Drainage

Well Drained

Petunia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Start indoors: Jan 29 Transplant: Mar 26 🌸 Bloom: Jun 4 – Oct 1
Recommended (50%) ✓ Fits season (22 days to spare)
Start indoors: Feb 7 Transplant: Apr 4 🌸 Bloom: Jun 13 – Oct 10
Safe Start (90%) ✓ Fits season (30 days to spare)
Start indoors: Feb 20 Transplant: Apr 17 🌸 Bloom: Jun 26 – Oct 23

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 Pittsburg County

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

Soil pH

Your soil pH (6.6–7.2) overlaps with Petunia's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). Annual compost additions will help Petunia.

How to Plant Petunia

12"
Between Plants
12"
Between Rows

Succession Planting Petunia

3
successive plantings in your 211-day season

Sow every 8 weeks. Last sowing by Aug 03 to harvest before frost.

Petunia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 659 gal / 100 sq ft

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 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 5.1" 0" ✅ Rainfall sufficient
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 2" 2.3" 🚿 Regular watering
Nov 4.3" 1" 3.3" 🚿 Regular watering
Dec 1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Pittsburg 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 ~1,400 GDD — county provides 3,692 GDD Excellent fit

Petunia Planting Timeline — Pittsburg County, OK

Petunia Planting Calendar

Activity When Date Range
Start Indoors February 7 Feb 7 – Feb 21
Transplant Outdoors April 4 Apr 4 – Apr 18
Bloom June 13 Jun 13 – Oct 10

· 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

1"/week · 1-2 times/week

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

211 days in Pittsburg County

Growing Tips for Petunia in Pittsburg County

Direct sow Petunia outdoors after April 04 in Pittsburg 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 Pittsburg County, OK?

Pittsburg County is in Zone 7b with an average last frost of April 4. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pittsburg County, OK?

Pittsburg County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is November 1.

🌱

Your Pittsburg County Garden Planner — Free

A 22-page printable planner built for Pittsburg County (Zone 7b). 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 Pittsburg County, OK. Local conditions may vary. Last updated: July 2026.

Sources & credits

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