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When to plant Petunia in Monroe County, FL

Monroe County's short 365-day growing season means one Petunia planting between November 20 and December 4. No fall crop in Zone 11b.

When to Plant Petunia in Monroe County, FL

Monroe County, Florida Zone 11b June

June in the garden — Monroe County, Florida

Your Monroe County, Florida garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost January 22
Soil temp (4") 88°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Basket week: petunia

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Before July arrives, get these ready
  • 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.

Monroe County, Florida is in USDA Zone 11b. The average last spring frost is January 22 and the first fall frost is April 15, giving you a growing season of approximately 83 days.

At an elevation of 169 feet, Monroe County receives approximately 55.6 inches of rainfall annually with predominantly sand soil. Summer highs average 93°F, providing good warmth for Petunia during the growing season. 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
Monroe County, FL (Zone 11b) Year-round
365 days
Last Spring Frost No frost
365 growing days
First Fall Frost No frost

Monroe County Soil Profile

Soil Type

Sand

Soil pH

4.8-5.7

Drainage

Well Drained

Soil Compatibility in Monroe County

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

Soil pH

Your soil pH (4.8–5.7) is more acidic than Petunia prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Monroe County warms quickly in spring but drains fast. Petunia will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Petunia.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting Petunia.

How to Plant Petunia

12"
Between Plants
12"
Between Rows

Petunia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 2,145 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 4.3" 2.3" 2" 💧 Light watering
Feb 4.3" 2.7" 1.6" 💧 Light watering
Mar 4.3" 3.8" 0.5" 💧 Light watering
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 7.1" 0" ✅ Rainfall sufficient
Jul 4.3" 8.2" 0" ✅ Rainfall sufficient
Aug 4.3" 8.7" 0" ✅ Rainfall sufficient
Sep 4.3" 7.7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.8" 0" ✅ Rainfall sufficient
Nov 2.2" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Jan–Oct in Monroe 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 7,208 GDD Excellent fit

Petunia Planting Timeline — Monroe County, FL

Petunia Planting Calendar

Activity When Date Range
Start Indoors November 27 Nov 27 – Dec 11
Transplant Outdoors November 20 Nov 20 – Dec 4
Bloom January 29 Jan 29 – Sep 10

· 12" apart · Rows 12" apart

Month-by-Month Timeline

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

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: too_acidic

🗺️ USDA Zone

Zone 11b

📆 Growing Season

365 days in Monroe County

Growing Tips for Petunia in Monroe County

Direct sow Petunia outdoors after January 22 in Monroe County when soil has warmed and frost danger has passed.

Sandy soil in Monroe County dries quickly — mulch Petunia with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Monroe County, FL?

Monroe County is in Zone 11b with an average last frost of January 22. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Monroe County, FL?

Monroe County, Florida is in USDA Hardiness Zone 11b. The average last spring frost is January 22 and first fall frost is .

When should I plant Petunia in Monroe County, FL?

In Monroe County, FL, plant Petunia after the last frost (around January 1) and before the first frost (around December 31). Best results when soil holds above 50°F.

What growing zone is Monroe County, FL for Petunia?

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

Can Petunia grow in Monroe County's climate?

Yes — Petunia grows well in Monroe County's temperate climate. Monroe County averages a 365-day frost-free season, with last frost around January 1 and first frost around December 31.

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Your Monroe County Garden Planner — Free

A 22-page printable planner built for Monroe County (Zone 11b). 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 Monroe County, FL. 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.