When to plant borage in Columbus, Ohio

April 20 – May 4

Direct-sow outdoors · typical Columbus year

Climate basis: NOAA station Columbus Wcmh, OH (USC00331785), 4 mi (7 km) from downtown Columbus (ZCTA 43215 centroid), elevation 740 ft, on the 1991–2020 climate normals. Direct-sow borage from approximately the dates above, anchored to the median last spring 32°F freeze (April 20). One year in ten still freezes after May 7.

Last spring freezeApril 201-in-10 after May 7
First fall freezeOctober 241-in-10 before Oct 13
Frost-free season185 daysmedian at 32°F
Hard freeze, 28°Apr 8Nov 3kills even hardy greens
USDA zone6b-5 to 0°F winter low not frost timing

The Columbus year

Start seeds indoorsMar 9 – Mar 23
Direct-sow outdoorsApr 20 – May 4
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to May 7
Borage in Columbus · freeze context from Columbus Wcmh, OH, 1991–2020 normals.

Every method, with its sources

Start seeds indoors

Mar 9 – Mar 23

Illinois Extension permits starting borage indoors but gives no lead time, so the offset comes from Virginia Cooperative Extension's herb publication — whose annual herb table lists borage — which sows small herb seed about six weeks before the last frost date. Anchored to the median last spring freeze (Apr 20). Virginia Cooperative Extension, Virginia Tech

Direct-sow outdoors

Apr 20 – May 4

Illinois Extension sows borage directly in the garden after frost is past, a point rule that opens a two-week sowing span at the last spring freeze. Anchored to the median last spring freeze (Apr 20). University of Illinois Extension · Virginia Cooperative Extension, Virginia Tech

Variety assumption: Virginia Cooperative Extension lists borage as a self-sowing annual; it resents root disturbance, so direct sowing is the usual method.

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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