When to plant leeks in Cleveland, Ohio

March 11 – March 25

Transplant outdoors · typical Cleveland year

Climate basis: NOAA station Cleveland Burke AP, OH (USW00004853), 2 mi (4 km) from downtown Cleveland (ZCTA 44113 centroid), elevation 584 ft, on the 1991–2020 climate normals. Transplant leeks outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (April 8). One year in ten still freezes after April 20.

Last spring freezeApril 81-in-10 after Apr 20
First fall freezeNovember 121-in-10 before Nov 1
Frost-free season217 daysmedian at 32°F
Hard freeze, 28°Apr 1Nov 22kills even hardy greens
USDA zone7a0 to 5°F winter low not frost timing

The Cleveland year

Start seeds indoorsDec 31 – Jan 14
Transplant outdoorsMar 11 – Mar 25
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Apr 20
Leeks in Cleveland · freeze context from Cleveland Burke AP, OH, 1991–2020 normals.

Every method, with its sources

Start seeds indoors

Dec 31 – Jan 14

Sow 8–10 weeks before the set-out window opens (UNH: time from seed to transplant 8–10 weeks). Anchored to the median last spring freeze (Apr 8). University of New Hampshire Extension

Transplant outdoors

Mar 11 – Mar 25

UNH: safe to set out 4 weeks before the last frost; Purdue's hardy class allows 4–6 weeks before. The later UNH start is used. Anchored to the median last spring freeze (Apr 8). University of New Hampshire Extension · Purdue University Extension

Direct-sow outdoors

Not calculated

Leeks are typically transplanted (Purdue marks leek 'typically transplanted'); the cited guides do not time direct sowing.

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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