Phlox Planting Guide

June

June is for phlox

Whether you're sowing, transplanting, or harvesting, phlox needs the right timing. Check your zone below for exact dates.

Sun full sun

Water moderate

Days to harvest 80–110

Plant depth 0.3″

Spacing 18″

How to water phlox
Consistent moisture matters more than volume for phlox. Little and often beats occasional drenching.
Where to put phlox
South-facing beds are ideal for phlox. Shade from nearby trees or fences costs real production.
Check your local forecast before planting
Your zone determines the exact week to plant phlox. Pick your county below and we'll line everything up against your frost dates.

Get phlox planting dates for your county →

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.

Phlox paniculata · Flower · Polemoniaceae family · 80–110 days to maturity

Perennial Blooms in Summer Pollinator-friendly Good for cutting Fragrant

Why it matters: If you're just starting a flower garden in your area, Phlox is a forgiving first pick. It tolerates imperfect soil, mild drought, and the occasional missed watering. The reward: weeks (sometimes months) of continuous color.

Get Your Personalized Phlox Planting Dates

Enter your ZIP code to see exact planting dates, soil compatibility, and growing tips specific to your county.

Where Can You Grow Phlox?

Zone Compatibility for Phlox Zones 3a – 9a

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Ideal (data available) Suitable Marginal Not recommended

Planting Dates by Zone

Zone	Start Indoors	Direct Sow	Transplant	Bloom
Zone 3a	Mar 6	May 29	May 29	Aug 21 – Oct 16
Zone 3b	Mar 1	May 24	May 24	Aug 16 – Oct 11
Zone 4a	Feb 25	May 20	May 20	Aug 12 – Oct 14
Zone 4b	Feb 20	May 15	May 15	Aug 7 – Oct 16
Zone 5a	Feb 21	May 9	May 9	Jul 25 – Oct 10
Zone 5b	Feb 14	May 2	May 2	Jul 18 – Oct 10
Zone 6a	Feb 6	Apr 17	Apr 17	Jun 26 – Sep 18
Zone 6b	Jan 30	Apr 10	Apr 10	Jun 19 – Sep 11
Zone 7a	Jan 21	Apr 1	Apr 1	Jun 10 – Sep 2
Zone 7b	Jan 14	Mar 25	Mar 25	Jun 3 – Aug 26
Zone 8a	Jan 11	Mar 8	Mar 8	May 17 – Jul 26
Zone 8b	Dec 31	Feb 25	Feb 25	May 6 – Jul 15
Zone 9a	Dec 16	Jan 27	Jan 27	Apr 7 – Jun 2

How to Plant Phlox

0.3"

Planting Depth

18"

Between Plants

24"

Between Rows

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Water when the top inch of soil feels dry. Consistent moisture produces the best results.

🧪 Soil pH

6 – 7

Prefers neutral to slightly acidic soil — ideal for most garden beds.

🗺️ Hardiness Zones

Zone 3a – 9a

📅 Days to Maturity

80–110 days

Medium-season crop. Start early for best results in shorter seasons.

👪 Plant Family

Polemoniaceae

Rotate with other families yearly to prevent soil-borne diseases. Don't plant in the same spot where Polemoniaceae family crops grew last year.

Succession Planting Phlox

Phlox matures in just 80–110 days, making it ideal for succession planting. In a typical 180-day growing season, you can get up to 2 successive plantings by sowing every 9.1 weeks.

Your actual succession count depends on your local frost dates. Enter your ZIP code to get personalized succession planting dates for your area.

Companion Planting for Phlox

✅ Good Companions

Echinacea Black Eyed Susan Yarrow Rudbeckia Bee Balm

Check more combinations with our Companion Planting Checker →

Growing Tips for Phlox

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.

Saving Phlox Seeds

Recommended for Your Garden

🌱

Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪

Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

🏷️

Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Reader favourite

Seed Saving & Storage Guide

$27 $157 value

Most saved seeds go bad before next season. This shows exactly when to pick, how to dry, and where to store seeds from 200 plants so yours don't.

200 plants, step-by-step: life cycle, pollination type, isolation
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Bonus: searchable Google Sheets tracker + custom GPT assistant

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Phlox by State

Frequently Asked Questions

How long does it take to grow Phlox?

Phlox (Phlox paniculata) takes 80 to 110 days from planting to harvest. Exact timing depends on your variety, growing conditions, and USDA zone.

What zones can Phlox grow in?

Phlox can be grown in USDA zones 3a through 9a. Use the planting calendar above to find the exact dates for your zone.

How much sun does Phlox need?

Growing Phlox requires Full Sun (6-8+ hours), Moderate — regular watering, and soil pH of 6 to 7.