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When to plant Phlox in Cheyenne County, KS

Aim to plant Phlox in Cheyenne County on or after May 11; the window stays open through June 1. Cheyenne County's 158-day frost-free season gives you a single solid spring crop with a brief fall option.

When to Plant Phlox in Cheyenne County, KS

Cheyenne County, Kansas Zone 6a June

What to do in June

We've pulled the most time-sensitive tasks for Cheyenne County, Kansas this June and put them front and centre. Tackle them in order.

Avg. last frost May 4
Avg. first frost October 9
Soil temp (4") 68°F
Watering High
Pest pressure High
Daylight 14.8 hrs
Get ahead of July
  • Starting indoors: phlox
  • 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.

Cheyenne County, Kansas is in USDA Zone 6a. The average last spring frost is May 4 and the first fall frost is October 9, giving you a growing season of approximately 158 days.

At an elevation of 967 feet, Cheyenne County receives approximately 24.3 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Phlox during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Cheyenne County, KS (Zone 6a) Moderate season
158 days
Last Spring Frost May 4
158 growing days
First Fall Frost October 9

Cheyenne County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Phlox Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Feb 26 Transplant: May 7 🌸 Bloom: Jul 16 – Oct 8
Recommended (50%) ✗ May not fit
Start indoors: Mar 2 Transplant: May 11 🌸 Bloom: Jul 20 – Oct 12
Safe Start (90%) ✗ May not fit
Start indoors: Mar 19 Transplant: May 28 🌸 Bloom: Aug 6 – Oct 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 Cheyenne County

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

Soil pH

Your soil pH (6.3–7.2) overlaps with Phlox's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Phlox.

Organic Matter

Organic matter is moderate (3.5%). 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 158-day season

Sow every 9.1 weeks. Last sowing by Jun 21 to harvest before frost.

Phlox Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,104 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 4.3" 2.6" 1.7" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 2.4" 1.9" 💧 Light watering
Aug 4.3" 2.5" 1.8" 💧 Light watering
Sep 4.3" 2" 2.3" 🚿 Regular watering
Oct 4.3" 2.3" 2" 💧 Light watering
Nov 1.7" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Cheyenne 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 ~1,378 GDD — county provides 2,291 GDD Excellent fit

Phlox Planting Timeline — Cheyenne County, KS

Phlox Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 11 May 11 – Jun 1
Bloom July 20 Jul 20 – Oct 12

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

158 days in Cheyenne County

Growing Tips for Phlox in Cheyenne County

Direct sow Phlox outdoors after May 04 in Cheyenne County when soil has warmed and frost danger has passed.

Cheyenne County receives only 24" of rain annually. Phlox needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Cheyenne County, KS?

Cheyenne County is in Zone 6a with an average last frost of May 4. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cheyenne County, KS?

Cheyenne County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is May 4 and first fall frost is October 9.

When should I plant Phlox in Cheyenne County, KS?

In Cheyenne County, KS, plant Phlox after the last frost (around May 4) and before the first frost (around October 9). Best results when soil holds above 50°F.

What growing zone is Cheyenne County, KS for Phlox?

Cheyenne County sits in USDA Zone 6a. Phlox grows reliably in zones 3a through 9a, so it's a good fit here.

Can Phlox grow in Cheyenne County's climate?

Yes — Phlox grows well in Cheyenne County's temperate climate. Cheyenne County averages a 158-day frost-free season, with last frost around May 4 and first frost around October 9.

🌱

Your Cheyenne County Garden Planner — Free

A 22-page printable planner built for Cheyenne County (Zone 6a). 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 Cheyenne 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.