When to plant borage in Louisville, Kentucky

March 31 – April 14

Direct-sow outdoors · typical Louisville year

Climate basis: NOAA station Louisville Mcalpine, KY (USC00154955), 3 mi (4 km) from downtown Louisville (ZCTA 40202 centroid), elevation 440 ft, on the 1991–2020 climate normals. Direct-sow borage from approximately the dates above, anchored to the median last spring 32°F freeze (March 31). One year in ten still freezes after April 14.

Last spring freezeMarch 311-in-10 after Apr 14
First fall freezeNovember 91-in-10 before Oct 31
Frost-free season225 daysmedian at 32°F
Hard freeze, 28°Mar 18Nov 20kills even hardy greens
USDA zone7a0 to 5°F winter low not frost timing

The Louisville year

Start seeds indoorsFeb 17 – Mar 3
Direct-sow outdoorsMar 31 – Apr 14
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Apr 14
Borage in Louisville · freeze context from Louisville Mcalpine, KY, 1991–2020 normals.

Every method, with its sources

Start seeds indoors

Feb 17 – Mar 3

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 (Mar 31). Virginia Cooperative Extension, Virginia Tech

Direct-sow outdoors

Mar 31 – Apr 14

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 (Mar 31). 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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