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When to plant sunflowers in zone 2a

In zone 2a, where the last spring frost typically comes around May 19, sow outdoors May 21 to June 11.

The zone 2a schedule for sunflowers

Sow outdoors
May 21 to June 11
Soil warm enough (50°F), about
May 21
Safest planting date (10% frost risk)
June 1
First harvest, roughly
July 10 to September 9

From the median frost dates of the NOAA stations assigned to the 10 ZIP codes in zone 2a, and the timing recommended by Cooperative Extension guides for sunflowers.

Frost risk in zone 2a

Zones are based on winter cold, not on frost dates, so the last spring frost varies a lot within a zone. Across zone 2a, the typical last frost ranges from about May 13 in the earliest tenth of ZIP codes to May 25 in the latest tenth, and the first fall frost from September 1 to September 13. For a typical place in the zone:

  • May 8Risky: a later frost happens in 9 years out of 10
  • May 19Typical: frost after this date in half of years
  • June 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

How to grow sunflowersAll zonesSunflowers in zone 3aAbout zone 2a

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