When to Plant Phlox in Bernalillo County, NM
This month in Bernalillo County, New Mexico
Welcome to June in Zone 7b. These are the moves that will have the biggest impact on your growing season.
July will be here before you know it — start on
- Starting indoors: phlox
- 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.
Bernalillo County, New Mexico is in USDA Zone 7b. The average last spring frost is April 30 and the first fall frost is October 14, giving you a growing season of approximately 167 days.
At an elevation of 4,326 feet, Bernalillo County receives approximately 16.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Phlox during the growing season. 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.
Bernalillo County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.8-8.2
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 Bernalillo County
How your county's soil matches Phlox's growing requirements.
Soil pH
Your soil pH (6.8–8.2) is more alkaline than Phlox prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Bernalillo 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 (0.7%). Add 2-3 inches of compost before planting Phlox.
How to Plant Phlox
Succession Planting Phlox
Sow every 9.1 weeks. Last sowing by Jun 26 to harvest before frost.
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 | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| May | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Jun | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Jul | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Aug | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Sep | 4.3" | 2.3" | 2" | 💧 Light watering |
| Oct | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Bernalillo 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 — Bernalillo County, NM
Phlox Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 26 | Feb 26 – Mar 12 |
| Transplant Outdoors | May 7 | May 7 – May 21 |
| Direct Sow | May 7 | May 7 – May 28 |
| Bloom | July 16 | Jul 16 – Oct 8 |
Plant 0.3" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| 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 7b
📆 Growing Season
167 days in Bernalillo County
Growing Tips for Phlox in Bernalillo County
Direct sow Phlox outdoors after April 30 in Bernalillo County when soil has warmed and frost danger has passed.
Sandy soil in Bernalillo County dries quickly — mulch Phlox with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Bernalillo County receives only 16" 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 Bernalillo County, NM?
Bernalillo County is in Zone 7b with an average last frost of April 30. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bernalillo County, NM?
Bernalillo County, New Mexico is in USDA Hardiness Zone 7b. The average last spring frost is April 30 and first fall frost is October 14.
Your Bernalillo County Garden Planner — Free
A 22-page printable planner built for Bernalillo 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.