When to Plant Phlox in California

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.

California spans USDA hardiness zones 6b, 7a, 7b, 8a, 8b, 9a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

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Click your county for exact Phlox planting dates based on your local frost dates.

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Phlox Planting Calendar for California

▸ Zone 6b ~205 day growing season · Full guide →

Last frost: April 3 · First frost: October 25 · 205 day season

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

▸ Zone 7a ~221 day growing season · Full guide →

Last frost: March 25 · First frost: November 1 · 221 day season

Activity	When	Date Range
Start Indoors	January 21	Jan 21 – Feb 4
Transplant Outdoors	April 1	Apr 1 – Apr 15
Direct Sow	April 1	Apr 1 – Apr 22
Bloom	June 10	Jun 10 – Sep 2

▸ Zone 7b ~235 day growing season · Full guide →

Last frost: March 18 · First frost: November 8 · 235 day season

Activity	When	Date Range
Start Indoors	January 14	Jan 14 – Jan 28
Transplant Outdoors	March 25	Mar 25 – Apr 8
Direct Sow	March 25	Mar 25 – Apr 15
Bloom	June 3	Jun 3 – Aug 26

▸ Zone 8a ~255 day growing season · Full guide →

Last frost: March 8 · First frost: November 18 · 255 day season

Activity	When	Date Range
Start Indoors	January 11	Jan 11 – Jan 25
Transplant Outdoors	March 8	Mar 8 – Mar 22
Direct Sow	March 8	Mar 8 – Mar 29
Bloom	May 17	May 17 – Jul 26

▸ Zone 8b ~276 day growing season · Full guide →

Last frost: February 25 · First frost: November 28 · 276 day season

Activity	When	Date Range
Start Indoors	December 31	Dec 31 – Jan 14
Transplant Outdoors	February 25	Feb 25 – Mar 11
Direct Sow	February 25	Feb 25 – Mar 18
Bloom	May 6	May 6 – Jul 15

▸ Zone 9a ~303 day growing season · Full guide →

Last frost: February 10 · First frost: December 10 · 303 day season

Activity	When	Date Range
Start Indoors	December 16	Dec 16 – Dec 30
Transplant Outdoors	January 27	Jan 27 – Feb 10
Direct Sow	January 27	Jan 27 – Feb 17
Bloom	April 7	Apr 7 – Jun 2

Growing Tips for California

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.

Phlox in Other States

Frequently Asked Questions

When should I plant Phlox in California?

Planting dates for Phlox in California depend on your USDA zone. California spans zones 6b, 7a, 7b, 8a, 8b, 9a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is California for planting?

California contains USDA hardiness zones 6b, 7a, 7b, 8a, 8b, 9a. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

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