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When to plant Phlox in Simpson County County,

Simpson County County gardeners should plant Phlox between April 13 and May 4 in spring. With Simpson County County's Zone 7a climate (last frost April 6), Phlox needs 110 days to mature — plant by July 11 for a full harvest.

When to Plant Phlox in Simpson County, KY

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.

Simpson County, Kentucky is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.

At an elevation of 3,996 feet, Simpson County receives approximately 49.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Phlox during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Simpson County, KY (Zone 7a) Long season
206 days
Last Spring Frost April 6
206 growing days
First Fall Frost October 29
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Simpson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.7

Drainage

Well Drained

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 4.1" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 5.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 4" 0" ❄️ Dormant
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Simpson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Phlox Planting Timeline — Simpson County, KY

Phlox Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow April 13 Apr 13 – May 4
Bloom June 22 Jun 22 – Sep 14

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

Moderate — regular watering

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 7a

📆 Growing Season

206 days in Simpson County

Growing Tips for Simpson County

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 Simpson County, KY?

Simpson County is in Zone 7a with an average last frost of April 6. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Simpson County, KY?

Simpson County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 29.

When should I plant Phlox in Simpson County County, ?

In Simpson County County, , plant Phlox after the last frost (around April 6) and before the first frost (around October 29). Best results when soil holds above 50°F.

What growing zone is Simpson County County, for Phlox?

Simpson 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 Simpson County County's climate?

Yes — Phlox grows well in Simpson County County's temperate climate. Simpson County County averages a 206-day frost-free season, with last frost around April 6 and first frost around October 29.

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Your Simpson County Garden Planner — Free

A 22-page printable planner built for Simpson 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 Simpson County, KY. Local conditions may vary. Last updated: June 2026.

Sources & credits

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