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When to Plant Phlox in Burnet County, TX

Burnet County, Texas Zone 8b June

June to-do list for Burnet County, Texas

Here's what deserves your attention in Burnet County, Texas this month. Everything below is tailored to Zone 8b and timed around your local frost dates.

Avg. last frost March 6
Avg. first frost November 20
Soil temp (4") 84°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Collect phlox at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Get ahead of July
  • 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.

Burnet County, Texas is in USDA Zone 8b. The average last spring frost is March 6 and the first fall frost is November 20, giving you a growing season of approximately 259 days.

At an elevation of 1,090 feet, Burnet County receives approximately 60.6 inches of rainfall annually with predominantly clay 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.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Burnet County, TX (Zone 8b) Long season
259 days
Last Spring Frost March 6
259 growing days
First Fall Frost November 20

Burnet County Soil Profile

Soil Type

Clay

Soil pH

6.8-7.6

Drainage

Well Drained

Phlox Planting Risk Windows

Early Start (70% safe) ✓ Fits season (116 days to spare)
Start indoors: Jan 2 Transplant: Feb 27 🌸 Bloom: May 8 – Jul 17
Recommended (50%) ✓ Fits season (119 days to spare)
Start indoors: Jan 9 Transplant: Mar 6 🌸 Bloom: May 15 – Jul 24
Safe Start (90%) ✓ Fits season (104 days to spare)
Start indoors: Feb 13 Transplant: Apr 10 🌸 Bloom: Jun 19 – Aug 28

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 Burnet County

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

Soil pH

Your soil pH (6.8–7.6) is more alkaline than Phlox prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Burnet County is workable for Phlox. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Phlox.

How to Plant Phlox

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

Succession Planting Phlox

3
successive plantings in your 259-day season

Sow every 9.1 weeks. Last sowing by Aug 02 to harvest before frost.

Phlox Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 40 gal / 100 sq ft

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 1.4" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 4.3" 3.2" 1.1" 💧 Light watering
Apr 4.3" 6.8" 0" ✅ Rainfall sufficient
May 4.3" 9.3" 0" ✅ Rainfall sufficient
Jun 4.3" 10.2" 0" ✅ Rainfall sufficient
Jul 4.3" 6.9" 0" ✅ Rainfall sufficient
Aug 4.3" 7.5" 0" ✅ Rainfall sufficient
Sep 4.3" 6.3" 0" ✅ Rainfall sufficient
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Burnet 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 ~1,876 GDD — county provides 5,115 GDD Excellent fit

Phlox Planting Timeline — Burnet County, TX

Phlox Planting Calendar

Activity When Date Range
Start Indoors January 9 Jan 9 – Jan 23
Transplant Outdoors March 6 Mar 6 – Mar 20
Direct Sow March 6 Mar 6 – Mar 27
Bloom May 15 May 15 – Jul 24

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8b

📆 Growing Season

259 days in Burnet County

Growing Tips for Phlox in Burnet County

Direct sow Phlox outdoors after March 06 in Burnet County when soil has warmed and frost danger has passed.

With Burnet County's clay soil (38% 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 →

Frequently Asked Questions

When should I plant Phlox in Burnet County, TX?

Burnet County is in Zone 8b with an average last frost of March 6. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Burnet County, TX?

Burnet County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 6 and first fall frost is November 20.

🌱

Your Burnet County Garden Planner — Free

A 22-page printable planner built for Burnet County (Zone 8b). 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 Burnet County, TX. 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.