When to plant sweet corn in Anchorage, Alaska

May 15 – May 29

Direct-sow outdoors · typical Anchorage year

Climate basis: NOAA station Anchorage Merrill Fld, AK (USW00026409), 0 mi (0 km) from downtown Anchorage (ZCTA 99501 centroid), elevation 138 ft, on the 1991–2020 climate normals. Direct-sow sweet corn from approximately the dates above, anchored to the median last spring 32°F freeze (May 1). One year in ten still freezes after May 9.

Last spring freezeMay 11-in-10 after May 9
First fall freezeSeptember 291-in-10 before Sep 17
Frost-free season150 daysmedian at 32°F
Hard freeze, 28°Apr 19Oct 8kills even hardy greens
USDA zone5a-20 to -15°F winter low not frost timing

The Anchorage year

Direct-sow outdoorsMay 15 – May 29
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to May 9
Sweet corn in Anchorage · freeze context from Anchorage Merrill Fld, AK, 1991–2020 normals.

Every method, with its sources

Direct-sow outdoors

May 15 – May 29

UGA: wait until at least two weeks after the last average killing frost. Purdue lists corn as tender (after last frost) and UNH keys sowing to 60°F soil; the later UGA rule is used. Anchored to the median last spring freeze (May 1). University of Georgia Cooperative Extension · Purdue University Extension · University of New Hampshire Extension

Start seeds indoors

Not calculated

The cited guides time sweet corn by direct seeding only.

Transplant outdoors

Not calculated

The cited extension guides do not time an outdoor transplanting window for this crop.

Fall planting

Not calculated

No source-backed fall planting rule exists for this crop in the registry, so no fall window is calculated.

Variety assumption: Assumes a mid-season hybrid (about 70–85 days; Penn State lists 80).

These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.

This week, not a typical year:
Crop rule sources (3)

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