When to plant sweet marjoram in Omaha, Nebraska

April 18 – May 2

Transplant outdoors · typical Omaha year

Climate basis: NOAA station Omaha Eppley Airfield, NE (USW00014942), 4 mi (6 km) from downtown Omaha (ZCTA 68102 centroid), elevation 982 ft, on the 1991–2020 climate normals. Transplant sweet marjoram outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (April 18). One year in ten still freezes after April 30.

Last spring freezeApril 181-in-10 after Apr 30
First fall freezeOctober 211-in-10 before Oct 6
Frost-free season185 daysmedian at 32°F
Hard freeze, 28°Apr 8Oct 30kills even hardy greens
USDA zone6a-10 to -5°F winter low not frost timing

The Omaha year

Start seeds indoorsFeb 21 – Mar 7
Transplant outdoorsApr 18 – May 2
Direct-sow outdoorsApr 4 – Apr 18
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Apr 30
Sweet Marjoram in Omaha · freeze context from Omaha Eppley Airfield, NE, 1991–2020 normals.

Every method, with its sources

Start seeds indoors

Feb 21 – Mar 7

NC State's Extension Gardener Plant Toolbox starts marjoram seed indoors about 6 to 8 weeks before the last spring frost date, and Clemson HGIC gives the identical 6-to-8-week lead, so the two sources agree. Anchored to the median last spring freeze (Apr 18). NC State Extension, North Carolina Extension Gardener Plant Toolbox · Clemson University Cooperative Extension, Home & Garden Information Center

Transplant outdoors

Apr 18 – May 2

Clemson HGIC sets marjoram transplants out after the last killing frost and UMD Extension names marjoram among herbs planted outside after the danger of frost has passed; both agree, so the window opens at the last spring freeze. Anchored to the median last spring freeze (Apr 18). Clemson University Cooperative Extension, Home & Garden Information Center

Direct-sow outdoors

Apr 4 – Apr 18

NC State's Extension Gardener Plant Toolbox gives a point rule — sow seed directly outdoors about two weeks before the last spring frost date — which opens a two-week sowing span ending at the last freeze; note the transplant window for this tender herb is later. Anchored to the median last spring freeze (Apr 18). NC State Extension, North Carolina Extension Gardener Plant Toolbox

Variety assumption: Grown as an annual across most of the US; NC State's plant toolbox treats it as a tender perennial that is replaced each year in cold climates.

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 (2)

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