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What to Plant in September — USDA Zone 9b

Here's everything you can start, transplant, sow, and harvest in September in USDA Zone 9b. This zone has an average last spring frost around January 25 and first fall frost around December 20, with a growing season of approximately 329 days.

There are 19 planting activities for September in Zone 9b.

Zone 9b Year-round
329 days
❄
Last Spring Frost January 25
➔ 329 growing days ➔
❄
First Fall Frost December 20

Where Is Zone 9b?

AL — Zone 7b AL AR — Zone 7b AR AZ — Zone 8a AZ CA — Zone 9a CA CO — Zone 5a CO CT — Zone 6b CT DE — Zone 7a DE FL — Zone 9a FL GA — Zone 7b GA IA — Zone 5a IA ID — Zone 5b ID IL — Zone 5b IL IN — Zone 6a IN KS — Zone 6a KS KY — Zone 6b KY LA — Zone 8b LA MA — Zone 6a MA MD — Zone 7a MD ME — Zone 4b ME MI — Zone 5b MI MN — Zone 4a MN MO — Zone 6a MO MS — Zone 8a MS MT — Zone 4b MT NC — Zone 7a NC ND — Zone 3b ND NE — Zone 5a NE NH — Zone 5a NH NJ — Zone 7a NJ NM — Zone 6b NM NV — Zone 6b NV NY — Zone 5b NY OH — Zone 6a OH OK — Zone 7a OK OR — Zone 7a OR PA — Zone 6a PA RI — Zone 6b RI SC — Zone 8a SC SD — Zone 4a SD TN — Zone 7a TN TX — Zone 8a TX UT — Zone 5b UT VA — Zone 7a VA VT — Zone 4b VT WA — Zone 7a WA WI — Zone 4b WI WV — Zone 6a WV WY — Zone 4a WY AK — Zone 2a AK HI — Zone 11a HI
Zones: 1 2 3 4 5 6 7 8 9 10 11

Harvest in September

Plant Type Date Range Days to Maturity
Begonias Flower 70–90 days
Celosia Flower 60–90 days
Dahlias Flower 70–120 days
Daylily Flower 60–90 days
Gaillardia (Blanket Flower) Flower 70–100 days
Geraniums Flower 70–100 days
Gladiolus Flower 70–100 days
Impatiens Flower 60–75 days
Nasturtium Flower 55–65 days
Portulaca Flower 50–70 days
Rosemary Herb 80–180 days
Roses Flower 90–180 days
Salvia Flower 70–90 days
Strawberries Fruit 90–365 days
Sunflower Flower 70–100 days
Valerian Herb 120–180 days
Vinca (Annual) Flower 70–90 days
Yam Vegetable 180–330 days
Zinnia Flower 60–70 days

Other Months for Zone 9b

September Planting by State

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — local conditions may vary. Last updated: July 2026.

Sources & credits

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

Plant varieties + growing data

Soil survey + temperature data

Drought monitoring

Household-consumption benchmarks

Derived

Other

Frost dates

Modeling

Precipitation + climate normals

Curated

Pest + disease pressure

Local extension offices

Daylight hours + sun data

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