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When to plant sunflowers in zone 9b

In zone 9b, where the last spring frost typically comes around January 31, sow outdoors January 31 to February 21.

The zone 9b schedule for sunflowers

Sow outdoors
January 31 to February 21
Safest planting date (10% frost risk)
March 1
First harvest, roughly
March 22 to May 22

From the median frost dates of the NOAA stations assigned to the 1,459 ZIP codes in zone 9b, and the timing recommended by Cooperative Extension guides for sunflowers.

Frost risk in zone 9b

Zones are based on winter cold, not on frost dates, so the last spring frost varies a lot within a zone. Across zone 9b, the typical last frost ranges from about January 12 in the earliest tenth of ZIP codes to March 1 in the latest tenth, and the first fall frost from January 8 to December 28. For a typical place in the zone:

  • December 18Risky: a later frost happens in 9 years out of 10
  • January 31Typical: frost after this date in half of years
  • March 1Safe: a later frost only 1 year in 10

Sunflowers are killed by frost, so if you want to be safe, plant out after the safe date rather than the typical one, or be ready to cover plants on a cold night.

Your dates for sunflowers

Set your ZIP code at the top of the page and we will work out when to plant sunflowers where you live, from the frost records of the nearest NOAA weather station. Your ZIP code is remembered on this device only.

Enter your ZIP code

Sunflowers in zone 9b cities

CityTypical last frostPlantFall
Houston, TXJan 30Jan 30 to Feb 20—
Jacksonville, FLFeb 1Feb 1 to 22—
San Jose, CAJan 12Jan 12 to Feb 2—
Fresno, CAJan 14Feb 3 to 24—
Sacramento, CAJan 12Jan 28 to Feb 18—
Bakersfield, CAJan 17Jan 23 to Feb 13—
New Orleans, LAJan 24Jan 24 to Feb 14—
Henderson, NVJan 20Jan 21 to Feb 11—

How to grow sunflowersAll zonesSunflowers in zone 9aAbout zone 9b

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