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When to plant Petunia in Massac County, IL

Massac County sits in cold Zone 7a. Plant Petunia April 14–April 28 for the single annual harvest; the October 21 first frost closes the window.

When to Plant Petunia in Massac County, IL

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.

Massac County, Illinois is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 21, giving you a growing season of approximately 197 days.

At an elevation of 778 feet, Massac County receives approximately 36 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Petunia during the growing season.

Annual Blooms in Summer Pollinator-friendly Fragrant
Massac County, IL (Zone 7a) Moderate season
197 days
Last Spring Frost April 7
197 growing days
First Fall Frost October 21

Massac County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7

Drainage

Well Drained

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 1.3" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

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

Petunia Planting Timeline — Massac County, IL

Petunia Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors April 14 Apr 14 – Apr 28
Bloom June 23 Jun 23 – Oct 13

· 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 7a

📆 Growing Season

197 days in Massac County

Growing Tips for Massac 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 Massac County, IL?

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

What planting zone is Massac County, IL?

Massac County, Illinois is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 21.

When should I plant Petunia in Massac County, IL?

In Massac County, IL, plant Petunia after the last frost (around April 7) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Massac County, IL for Petunia?

Massac County sits in USDA Zone 7a. Petunia grows reliably in zones 2a through 11b, so it's a good fit here.

Can Petunia grow in Massac County's climate?

Yes — Petunia grows well in Massac County's temperate climate. Massac County averages a 197-day frost-free season, with last frost around April 7 and first frost around October 21.

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Your Massac County Garden Planner — Free

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

Sources & credits

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