When to plant Phlox in Union County County,
For Union County County, gardeners: plant Phlox April 18 through May 9 once soil reads 50°F.
When to Plant Phlox in Union County, GA
What to do in June
June is a pivotal month for Union County, Georgia gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Sow phlox in trays indoors
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
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Bring in the phlox
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
To set up a strong July, finish these tasks
- 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.
Union County, Georgia is in USDA Zone 7b. The average last spring frost is April 11 and the first fall frost is October 23, giving you a growing season of approximately 195 days.
At an elevation of 175 feet, Union County receives approximately 61.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 93°F, providing good warmth for Phlox during the growing season. Clay soil retains moisture well for Phlox, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Phlox root diseases.
Union County Soil Profile
Soil Type
Clay Loam
Soil pH
5.8-6.2
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 Union County
How your county's soil matches Phlox's growing requirements.
Soil pH
Your soil pH (5.8–6.2) overlaps with Phlox's range (6.0–7.0), though not a perfect match.
Soil Texture
The clay loam soil in Union County is excellent for Phlox — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Phlox.
How to Plant Phlox
Succession Planting Phlox
Sow every 9.1 weeks. Last sowing by Jul 05 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 | — | 6" | 0" | ❄️ Dormant |
| Feb | — | 4.6" | 0" | ❄️ Dormant |
| Mar | — | 5.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.7" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 6.2" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Nov | — | 4.2" | 0" | ❄️ Dormant |
| Dec | — | 5.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Union 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 — Union County, GA
Phlox Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 7 | Feb 7 – Feb 21 |
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 18 | Apr 18 – May 9 |
| Bloom | June 27 | Jun 27 – Sep 19 |
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
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
195 days in Union County
Growing Tips for Phlox in Union County
Direct sow Phlox outdoors after April 11 in Union County when soil has warmed and frost danger has passed.
With Union County's clay soil (28% clay), work in 3-4 inches of compost before planting Phlox. Avoid tilling when soil is wet to prevent compaction.
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 Union County, GA?
Union County is in Zone 7b with an average last frost of April 11. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union County, GA?
Union County, Georgia is in USDA Hardiness Zone 7b. The average last spring frost is April 11 and first fall frost is October 23.
When should I plant Phlox in Union County, ?
In Union County, , plant Phlox after the last frost (around April 11) and before the first frost (around October 23). Best results when soil holds above 50°F.
What growing zone is Union County, for Phlox?
Union County sits in USDA Zone 7b. 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 195-day frost-free season, with last frost around April 11 and first frost around October 23.
Your Union County Garden Planner — Free
A 22-page printable planner built for Union 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.