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When to plant Phlox in Bourbon County County,

Plant Phlox in Bourbon County County from April 15 to May 6 in spring. Bourbon County County sits in USDA Zone 7a, with last frost around April 8 and first frost on October 25.

When to Plant Phlox in Bourbon County, KS

Bourbon County, Kansas Zone 7a June

Your June game plan for Bourbon County, Kansas

Each item below is timed to Bourbon County, Kansas's frost dates and soil temperatures. Skip nothing, stress about nothing.

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. Start phlox under lights

    These need a head start before your last frost (April 8). Sow into cells now so you're ready to transplant in a few weeks.

  2. Start harvesting phlox

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

July prep starts now
  • First harvests: phlox

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Garden Phlox (Phlox paniculata) is a beloved native perennial of eastern North America, producing large, domed clusters of fragrant flowers atop upright stems from mid-summer into fall. Its sweet honey-like fragrance carries on summer evenings and draws hummingbirds, butterflies, and sphinx moths. Modern cultivars offer colors spanning white, pink, salmon, red, purple, and bicolors. A classic cottage garden stalwart, phlox combines well with black-eyed Susans, echinacea, and ornamental grasses in naturalistic plantings. Select mildew-resistant cultivars for best long-term performance.

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 Phlox during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Bourbon County, KS (Zone 7a) Long season
200 days
Last Spring Frost April 8
200 growing days
First Fall Frost October 25
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Bourbon County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Phlox Planting Risk Windows

Early Start (70% safe) ✓ Fits season (39 days to spare)
Start indoors: Jan 29 Transplant: Apr 9 🌸 Bloom: Jun 18 – Sep 10
Recommended (50%) ✓ Fits season (39 days to spare)
Start indoors: Feb 4 Transplant: Apr 15 🌸 Bloom: Jun 24 – Sep 16
Safe Start (90%) ✓ Fits season (37 days to spare)
Start indoors: Feb 17 Transplant: Apr 28 🌸 Bloom: Jul 7 – Sep 29

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 Phlox's growing requirements.

Soil pH

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

Soil Texture

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

Organic Matter

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

How to Plant Phlox

0.3"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Phlox

2
successive plantings in your 200-day season

Sow every 9.1 weeks. Last sowing by Jul 07 to harvest before frost.

Phlox 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 Phlox

Phlox needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Phlox 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.

Phlox 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.

Phlox needs ~1,306 GDD — county provides 2,750 GDD Excellent fit

Phlox Planting Timeline — Bourbon County, KS

Phlox Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 15 Apr 15 – May 6
Bloom June 24 Jun 24 – Sep 16

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

200 days in Bourbon County

Growing Tips for Phlox in Bourbon County

Direct sow Phlox outdoors after April 08 in Bourbon County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors 8–10 weeks before last frost, or transplant container divisions in spring. Named cultivar seeds may not come true; divisions from named plants are the preferred propagation method. Space generously (18–24 inches) and avoid overhead watering to reduce powdery mildew risk. Good air circulation is critical — thin clumps to the strongest 5–7 stems per plant in spring. Deadhead after the primary bloom flush to encourage secondary flowering. Division every 2–3 years in spring keeps plants vigorous. Fall planting of divisions (Zones 5+) is equally effective. Year 2+ plants develop into full clumps with the most prolific bloom.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Phlox in Bourbon County, KS?

Bourbon County is in Zone 7a with an average last frost of April 8. Plan your Phlox 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 Phlox in Bourbon County County, ?

In Bourbon County County, , plant Phlox 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 Phlox?

Bourbon County County sits in USDA Zone 7a. Phlox grows reliably in zones 3a through 9a, so it's a good fit here.

Can Phlox grow in Bourbon County County's climate?

Yes — Phlox 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.

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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 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.