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When to Plant Phlox in Okmulgee County, OK

Okmulgee County, Oklahoma Zone 7b June

Your June planting checklist for Okmulgee County, Oklahoma

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 3
Avg. first frost November 2
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.4 hrs
  1. Get phlox seeds going inside

    Label every cell. You will absolutely forget which is which otherwise.

  2. Start harvesting phlox

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Coming up in July — start thinking about
  • First harvests: phlox

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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.

Okmulgee County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is November 2, giving you a growing season of approximately 213 days.

At an elevation of 657 feet, Okmulgee County receives approximately 28.9 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Phlox during the growing season.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Okmulgee County, OK (Zone 7b) Long season
213 days
Last Spring Frost April 3
213 growing days
First Fall Frost November 2

Okmulgee County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.6

Drainage

Well Drained

Phlox Planting Risk Windows

Early Start (70% safe) ✓ Fits season (55 days to spare)
Start indoors: Jan 21 Transplant: Apr 1 🌸 Bloom: Jun 10 – Sep 2
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Jan 30 Transplant: Apr 10 🌸 Bloom: Jun 19 – Sep 11
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Feb 11 Transplant: Apr 22 🌸 Bloom: Jul 1 – Sep 23

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 Okmulgee County

How your county's soil matches Phlox's growing requirements.

Soil pH

Your soil pH (6.7–7.6) is more alkaline than Phlox prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Okmulgee County is excellent for Phlox — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) — Phlox will thrive.

How to Plant Phlox

0.3"
Planting Depth
18"
Between Plants
24"
Between Rows

Succession Planting Phlox

3
successive plantings in your 213-day season

Sow every 9.1 weeks. Last sowing by Jul 15 to harvest before frost.

Phlox Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 979 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.8" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 4.3" 1" 3.3" 🚿 Regular watering
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Okmulgee 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 needs ~1,734 GDD — county provides 3,887 GDD Excellent fit

Phlox Planting Timeline — Okmulgee County, OK

Phlox Planting Calendar

Activity When Date Range
Start Indoors January 30 Jan 30 – Feb 13
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow April 10 Apr 10 – May 1
Bloom June 19 Jun 19 – Sep 11

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March
April Transplant Outdoors Direct Sow
May Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

80–110 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

213 days in Okmulgee County

Growing Tips for Phlox in Okmulgee County

Direct sow Phlox outdoors after April 03 in Okmulgee 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 →

Frequently Asked Questions

When should I plant Phlox in Okmulgee County, OK?

Okmulgee County is in Zone 7b with an average last frost of April 3. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Okmulgee County, OK?

Okmulgee County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 3 and first fall frost is November 2.

🌱

Your Okmulgee County Garden Planner — Free

A 22-page printable planner built for Okmulgee 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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Okmulgee County, OK. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.