Blog

When to plant Petunia in Bourbon County County,

Plant Petunia in Bourbon County County, between April 15 and April 29 — the only viable window. Zone 7a's short season (200 frost-free days) rules out a fall crop.

When to Plant Petunia in Bourbon County, KS

Bourbon County, Kansas Zone 7a June

What to do in June

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Bourbon County, Kansas.

Avg. last frost April 8
Avg. first frost October 25
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.6 hrs
  1. Fire up the seed-starting tray: petunia

    You're about 19 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Start harvesting petunia

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

July prep starts now
  • 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.

Bourbon County, Kansas is in USDA Zone 7a. The average last spring frost is April 8 and the first fall frost is October 25, giving you a growing season of approximately 200 days.

At an elevation of 438 feet, Bourbon County receives approximately 26 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Petunia during the growing season.

Annual Blooms in Summer Pollinator-friendly Fragrant
Bourbon County, KS (Zone 7a) Long season
200 days
Last Spring Frost April 8
200 growing days
First Fall Frost October 25
Share this guide:

Bourbon County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Petunia Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Feb 5 Transplant: Apr 9 🌸 Bloom: Jun 18 – Oct 8
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Feb 11 Transplant: Apr 15 🌸 Bloom: Jun 24 – Oct 14
Safe Start (90%) ✓ Fits season (9 days to spare)
Start indoors: Feb 24 Transplant: Apr 28 🌸 Bloom: Jul 7 – Oct 27

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 Bourbon County

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

Soil pH

Your soil pH (6.2–7.2) overlaps with Petunia's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Petunia.

How to Plant Petunia

12"
Between Plants
12"
Between Rows

Succession Planting Petunia

3
successive plantings in your 200-day season

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

Petunia Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 808 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 3.2" 1.1" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Bourbon 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 ~1,100 GDD — county provides 2,750 GDD Excellent fit

Petunia Planting Timeline — Bourbon County, KS

Petunia Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Bloom June 24 Jun 24 – Oct 14

· 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
Share this guide:

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 7a

📆 Growing Season

200 days in Bourbon County

Growing Tips for Petunia in Bourbon County

Direct sow Petunia outdoors after April 08 in Bourbon 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 Bourbon County, KS?

Bourbon County is in Zone 7a with an average last frost of April 8. Plan your Petunia planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bourbon County, KS?

Bourbon County, Kansas is in USDA Hardiness Zone 7a. The average last spring frost is April 8 and first fall frost is October 25.

When should I plant Petunia in Bourbon County County, ?

In Bourbon County County, , plant Petunia after the last frost (around April 8) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Bourbon County County, for Petunia?

Bourbon County 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 Bourbon County County's climate?

Yes — Petunia grows well in Bourbon County County's temperate climate. Bourbon County County averages a 200-day frost-free season, with last frost around April 8 and first frost around October 25.

🌱

Your Bourbon County Garden Planner — Free

A 22-page printable planner built for Bourbon 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.

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 Bourbon County, KS. 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.