When to Plant Phlox in Dewey County, OK
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.
Dewey County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.
At an elevation of 745 feet, Dewey County receives approximately 28.5 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Phlox during the growing season.
Dewey County Soil Profile
Soil Type
Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Phlox Planting Timeline — Dewey County, OK
Phlox Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 9 | Feb 9 – Feb 23 |
| Transplant Outdoors | April 20 | Apr 20 – May 4 |
| Direct Sow | April 20 | Apr 20 – May 11 |
| Bloom | June 29 | Jun 29 – Sep 21 |
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 | Transplant Outdoors 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
194 days in Dewey County
Growing Tips for Dewey 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 Dewey County, OK?
Dewey County is in Zone 7a with an average last frost of April 13. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dewey County, OK?
Dewey County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 13 and first fall frost is October 24.
Your Dewey County Garden Planner — Free
A 22-page printable planner built for Dewey 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.