When to plant Phlox in Coconino County, AZ
Plant Phlox in Coconino County, between June 4 and June 25 — the only viable window. Zone 7a's short season (122 frost-free days) rules out a fall crop.
When to Plant Phlox in Coconino County, AZ
July in the garden — Coconino County, Arizona
July rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Coconino County, Arizona.
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Time to start phlox inside
Label every cell. You will absolutely forget which is which otherwise.
Looking ahead to August
- 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.
Coconino County, Arizona is in USDA Zone 7a. The average last spring frost is May 28 and the first fall frost is September 27, giving you a growing season of approximately 122 days.
At an elevation of 7,869 feet, Coconino County receives approximately 13.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Phlox may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Phlox will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Phlox successfully. Mulch heavily to conserve soil moisture.
Coconino County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.2-8.6
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 Coconino County
How your county's soil matches Phlox's growing requirements.
Soil pH
Your soil pH (7.2–8.6) is more alkaline than Phlox prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Coconino County warms quickly in spring but drains fast. Phlox will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Phlox.
Organic Matter
Organic matter is low (0.8%). Add 2-3 inches of compost before planting Phlox.
How to Plant Phlox
Phlox Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
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 | — | 1" | 0" | ❄️ Dormant |
| Feb | — | 0.7" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | — | 0.4" | 0" | ❄️ Dormant |
| May | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Jun | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jul | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Aug | 4.3" | 3" | 1.3" | 💧 Light watering |
| Sep | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Oct | — | 1.3" | 0" | ❄️ Dormant |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Coconino 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 — Coconino County, AZ
Phlox Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 26 | Mar 26 – Apr 9 |
| Transplant Outdoors | June 4 | Jun 4 – Jun 18 |
| Direct Sow | June 4 | Jun 4 – Jun 25 |
| Bloom | August 13 | Aug 13 – Nov 5 |
Plant 0.3" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | — |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | Bloom |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
80–110 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 7a
📆 Growing Season
122 days in Coconino County
Growing Tips for Phlox in Coconino County
Direct sow Phlox outdoors after May 28 in Coconino County when soil has warmed and frost danger has passed.
Sandy soil in Coconino County dries quickly — mulch Phlox with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 96°F in Coconino County, provide afternoon shade for Phlox and water deeply in the morning.
Your 122.0-day growing season in Coconino County is tight for Phlox (80.0-110.0 days to maturity). Start indoors and choose early-maturing varieties.
Coconino County receives only 14" of rain annually. Phlox needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
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 Coconino County, AZ?
Coconino County is in Zone 7a with an average last frost of May 28. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.
What planting zone is Coconino County, AZ?
Coconino County, Arizona is in USDA Hardiness Zone 7a. The average last spring frost is May 28 and first fall frost is September 27.
When should I plant Phlox in Coconino County, AZ?
In Coconino County, AZ, plant Phlox after the last frost (around May 28) and before the first frost (around September 27). Best results when soil holds above 50°F.
What growing zone is Coconino County, AZ for Phlox?
Coconino 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 Coconino County's climate?
Yes — Phlox grows well in Coconino County's temperate climate. Coconino County averages a 122-day frost-free season, with last frost around May 28 and first frost around September 27.
Your Coconino County Garden Planner — Free
A 22-page printable planner built for Coconino 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.