When to plant Phlox in Modoc County County,
In Modoc County County, Phlox is a spring-only crop. Plant June 7–June 28 once soil hits 50°F.
When to Plant Phlox in Modoc County, CA
Your June gardening checklist
We've pulled the most time-sensitive tasks for Modoc County, California this June and put them front and centre. Tackle them in order.
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Get phlox in the ground
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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Put phlox seeds straight in the ground
Your soil is 68°F — warm enough for these to germinate without babying.
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.
Modoc County, California is in USDA Zone 6b. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.
At an elevation of 2,205 feet, Modoc County receives approximately 28.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Phlox to ensure they mature before fall.
Modoc County Soil Profile
Soil Type
Loam
Soil pH
5.9-7.4
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 Modoc County
How your county's soil matches Phlox's growing requirements.
Soil pH
Your soil pH (5.9–7.4) overlaps with Phlox's range (6.0–7.0), though not a perfect match.
Soil Texture
The loam soil in Modoc 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 (2.1%). Annual compost additions will help Phlox.
How to Plant Phlox
Phlox Water Budget
Water stress score is 8/10 — 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 | — | 5.6" | 0" | ❄️ Dormant |
| Feb | — | 5.8" | 0" | ❄️ Dormant |
| Mar | — | 4.1" | 0" | ❄️ Dormant |
| Apr | — | 2.1" | 0" | ❄️ Dormant |
| May | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Jun | 4.3" | 0.1" | 4.2" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Oct | — | 1.3" | 0" | ❄️ Dormant |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 5.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Modoc 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 — Modoc County, CA
Phlox Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 29 | Mar 29 – Apr 12 |
| Transplant Outdoors | June 7 | Jun 7 – Jun 21 |
| Direct Sow | June 7 | Jun 7 – Jun 28 |
| Bloom | August 16 | Aug 16 – Nov 8 |
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 · Only during dry spells
📅 Days to Maturity
80–110 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 6b
📆 Growing Season
113 days in Modoc County
Growing Tips for Phlox in Modoc County
Direct sow Phlox outdoors after May 31 in Modoc County when soil has warmed and frost danger has passed.
Your 113.0-day growing season in Modoc County is tight for Phlox (80.0-110.0 days to maturity). Start indoors and choose early-maturing varieties.
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 Modoc County, CA?
Modoc County is in Zone 6b with an average last frost of May 31. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.
What planting zone is Modoc County, CA?
Modoc County, California is in USDA Hardiness Zone 6b. The average last spring frost is May 31 and first fall frost is September 21.
When should I plant Phlox in Modoc County County, ?
In Modoc County County, , plant Phlox after the last frost (around May 31) and before the first frost (around September 21). Best results when soil holds above 50°F.
What growing zone is Modoc County County, for Phlox?
Modoc County County sits in USDA Zone 6b. Phlox grows reliably in zones 3a through 9a, so it's a good fit here.
Can Phlox grow in Modoc County County's climate?
Yes — Phlox grows well in Modoc County County's temperate climate. Modoc County County averages a 113-day frost-free season, with last frost around May 31 and first frost around September 21.
Your Modoc County Garden Planner — Free
A 22-page printable planner built for Modoc County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.