When to Plant Phlox in Carter County, TN
Your June game plan for Carter County, Tennessee
June is a pivotal month for Carter County, Tennessee gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Fire up the seed-starting tray: phlox
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
Coming up in July — start thinking about
- First harvests: phlox
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.
Carter County, Tennessee is in USDA Zone 7b. The average last spring frost is April 16 and the first fall frost is October 22, giving you a growing season of approximately 189 days.
At an elevation of 3,776 feet, Carter County receives approximately 53.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Phlox during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Phlox root diseases.
Carter County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-7
Drainage
Well Drained
Phlox Planting Risk Windows
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 Carter County
How your county's soil matches Phlox's growing requirements.
Soil pH
Your soil pH (5.6–7.0) overlaps with Phlox's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Carter 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 (2.8%). Annual compost additions will help Phlox.
How to Plant Phlox
Succession Planting Phlox
Sow every 9.1 weeks. Last sowing by Jul 04 to harvest before frost.
Phlox Water Budget
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 | — | 4.8" | 0" | ❄️ Dormant |
| Feb | — | 4" | 0" | ❄️ Dormant |
| Mar | — | 5.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Nov | — | 3.7" | 0" | ❄️ Dormant |
| Dec | — | 4.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Carter 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 Planting Timeline — Carter County, TN
Phlox Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 12 | Feb 12 – Feb 26 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Bloom | July 2 | Jul 2 – Sep 24 |
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 | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
80–110 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
189 days in Carter County
Growing Tips for Phlox in Carter County
Direct sow Phlox outdoors after April 16 in Carter 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 →
Phlox in Other Locations
Frequently Asked Questions
When should I plant Phlox in Carter County, TN?
Carter County is in Zone 7b with an average last frost of April 16. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.
What planting zone is Carter County, TN?
Carter County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 16 and first fall frost is October 22.
Your Carter County Garden Planner — Free
A 22-page printable planner built for Carter County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.