When to plant Phlox in Union County, KY
Union County's spring Phlox window runs April 13 through May 4. most warm-season crops establish quickly once soil holds above 60°F.
When to Plant Phlox in Union 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.
Union County, Kentucky is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 31, giving you a growing season of approximately 208 days.
At an elevation of 1,482 feet, Union County receives approximately 48.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Phlox during the growing season.
Union County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Phlox Planting Timeline — Union 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
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
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
208 days in Union County
Growing Tips for Union 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 →
Phlox in Other Locations
Frequently Asked Questions
When should I plant Phlox in Union County, KY?
Union 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 Union County, KY?
Union County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 31.
When should I plant Phlox in Union County, KY?
In Union County, KY, plant Phlox after the last frost (around April 6) and before the first frost (around October 31). Best results when soil holds above 50°F.
What growing zone is Union County, KY for Phlox?
Union 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 Union County's climate?
Yes — Phlox grows well in Union County's temperate climate. Union County averages a 208-day frost-free season, with last frost around April 6 and first frost around October 31.
Your Union County Garden Planner — Free
A 22-page printable planner built for Union 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.