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When to plant Phlox in Clay County County,

Plant Phlox in Clay County County after April 14; the prime window is April 21–May 12.

When to Plant Phlox in Clay County, KS

Clay County, Kansas Zone 6b June

What to do in June

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

Avg. last frost April 14
Avg. first frost October 23
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 14.8 hrs
  1. Fire up the seed-starting tray: phlox

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Pick phlox

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Looking ahead to July
  • 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.

Clay County, Kansas is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 23, giving you a growing season of approximately 192 days.

At an elevation of 519 feet, Clay County receives approximately 28 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
Clay County, KS (Zone 6b) Moderate season
192 days
Last Spring Frost April 14
192 growing days
First Fall Frost October 23
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Clay County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.8

Drainage

Well Drained

Phlox Planting Risk Windows

Early Start (70% safe) ✓ Fits season (25 days to spare)
Start indoors: Feb 7 Transplant: Apr 18 🌸 Bloom: Jun 27 – Sep 19
Recommended (50%) ✓ Fits season (31 days to spare)
Start indoors: Feb 10 Transplant: Apr 21 🌸 Bloom: Jun 30 – Sep 22
Safe Start (90%) ✓ Fits season (28 days to spare)
Start indoors: Feb 23 Transplant: May 4 🌸 Bloom: Jul 13 – Oct 5

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 Clay County

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

Soil pH

Your soil pH (6.8–7.8) is more alkaline than Phlox prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Clay 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 192-day season

Sow every 9.1 weeks. Last sowing by Jul 05 to harvest before frost.

Phlox Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,410 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.8" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 4.3" 2.6" 1.7" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 3.6" 0.7" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Clay 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 2,640 GDD Excellent fit

Phlox Planting Timeline — Clay County, KS

Phlox Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 21 Apr 21 – May 12
Bloom June 30 Jun 30 – Sep 22

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 Transplant Outdoors 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 · 2-3 times/week

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

192 days in Clay County

Growing Tips for Phlox in Clay County

Direct sow Phlox outdoors after April 14 in Clay 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 Clay County, KS?

Clay County is in Zone 6b with an average last frost of April 14. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clay County, KS?

Clay County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 23.

When should I plant Phlox in Clay County, ?

In Clay County, , plant Phlox after the last frost (around April 14) and before the first frost (around October 23). Best results when soil holds above 50°F.

What growing zone is Clay County, for Phlox?

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

Can Phlox grow in Clay County's climate?

Yes — Phlox grows well in Clay County's temperate climate. Clay County averages a 192-day frost-free season, with last frost around April 14 and first frost around October 23.

🌱

Your Clay County Garden Planner — Free

A 22-page printable planner built for Clay County (Zone 6b). 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 Clay 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.