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When to plant Phlox in Alachua County, FL

In Alachua County, plant Phlox in spring between February 9 and March 2, once soil temps hold above 50°F. Alachua County's last frost averages February 23, so aim for a steady week of warm soil before planting. For a fall crop, sow between and — roughly 80–110 days before the first frost on November 27.

When to Plant Phlox in Alachua County, FL

Alachua County, Florida Zone 9a July

Your July game plan for Alachua County, Florida

Each item below is timed to Alachua County, Florida's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 23
Avg. first frost November 27
Soil temp (4") 95°F
Watering Low
Pest pressure High
Daylight 13.7 hrs

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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.

Alachua County, Florida is in USDA Zone 9a. The average last spring frost is February 23 and the first fall frost is November 27, giving you a growing season of approximately 277 days.

At an elevation of 398 feet, Alachua County receives approximately 50 inches of rainfall annually with predominantly sand soil. Summer highs average 99°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.

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant
Alachua County, FL (Zone 9a) Year-round
277 days
Last Spring Frost February 23
277 growing days
First Fall Frost November 27

Alachua County Soil Profile

Soil Type

Sand

Soil pH

5.2-6.1

Drainage

Well Drained

Phlox Planting Risk Windows

Early Start (70% safe) ✓ Fits season (166 days to spare)
Start indoors: Dec 20 Transplant: Jan 31 🌸 Bloom: Apr 11 – Jun 6
Recommended (50%) ✓ Fits season (165 days to spare)
Start indoors: Dec 29 Transplant: Feb 9 🌸 Bloom: Apr 20 – Jun 15
Safe Start (90%) ✓ Fits season (159 days to spare)
Start indoors: Jan 27 Transplant: Mar 10 🌸 Bloom: May 19 – Jul 14

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 Alachua County

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

Soil pH

Your soil pH (5.2–6.1) is more acidic than Phlox prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Alachua 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 (1.6%). Add 2-3 inches of compost before planting Phlox.

How to Plant Phlox

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

Succession Planting Phlox

4
successive plantings in your 277-day season

Sow every 9.1 weeks. Last sowing by Aug 09 to harvest before frost.

Phlox Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,617 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 2.6" 0" ❄️ Dormant
Feb 4.3" 2.7" 1.6" 💧 Light watering
Mar 4.3" 2.7" 1.6" 💧 Light watering
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 7.5" 0" ✅ Rainfall sufficient
Jul 4.3" 7.4" 0" ✅ Rainfall sufficient
Aug 4.3" 6.3" 0" ✅ Rainfall sufficient
Sep 4.3" 6.8" 0" ✅ Rainfall sufficient
Oct 4.3" 4.6" 0" ✅ Rainfall sufficient
Nov 4.3" 1.9" 2.4" 🚿 Regular watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Alachua 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 ~2,304 GDD — county provides 6,741 GDD Excellent fit

Phlox Planting Timeline — Alachua County, FL

Phlox Planting Calendar

Activity When Date Range
Start Indoors December 29 Dec 29 – Jan 12
Transplant Outdoors February 9 Feb 9 – Feb 23
Direct Sow February 9 Feb 9 – Mar 2
Bloom April 20 Apr 20 – Jun 15

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

Month-by-Month Timeline

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

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_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Alachua County

Growing Tips for Phlox in Alachua County

Direct sow Phlox outdoors after February 23 in Alachua County when soil has warmed and frost danger has passed.

Sandy soil in Alachua 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 99°F in Alachua County, provide afternoon shade for Phlox and water deeply in the morning.

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 Alachua County, FL?

Alachua County is in Zone 9a with an average last frost of February 23. Plan your Phlox planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alachua County, FL?

Alachua County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 23 and first fall frost is November 27.

When should I plant Phlox in Alachua County, FL?

In Alachua County, FL, plant Phlox after the last frost (around February 23) and before the first frost (around November 27). Best results when soil holds above 50°F.

What growing zone is Alachua County, FL for Phlox?

Alachua County sits in USDA Zone 9a. Phlox grows reliably in zones 3a through 9a, so it's a good fit here.

Can Phlox grow in Alachua County's climate?

Yes — Phlox grows well in Alachua County's temperate climate. Alachua County averages a 278-day frost-free season, with last frost around February 23 and first frost around November 27.

🌱

Your Alachua County Garden Planner — Free

A 22-page printable planner built for Alachua County (Zone 9a). 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 Alachua County, FL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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