PlantingWindowThe American Planting Almanac

When to plant borage in Boston, Massachusetts

April 4 – April 18

Direct-sow outdoors · typical Boston year

Climate basis: NOAA station Boston Logan INTL AP, MA (USW00014739), 3 mi (5 km) from downtown Boston (ZCTA 02108 centroid), elevation 12 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 4). One year in ten still freezes after April 17.

Last spring freezeApril 41-in-10 after Apr 17
First fall freezeNovember 91-in-10 before Oct 29
Frost-free season≈ 218 daysmedian at 32°F
Hard freeze, 28°Mar 28 – Nov 21kills even hardy greens
USDA zone7a0 to 5°F winter low — not frost timing

The Boston year

Start seeds indoorsFeb 21 – Mar 7
Direct-sow outdoorsApr 4 – Apr 18
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Apr 17
Borage in Boston · freeze context from Boston Logan INTL AP, MA, 1991–2020 normals.

Every method, with its sources

Start seeds indoors

Feb 21 – Mar 7

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 4). Virginia Cooperative Extension, Virginia Tech

Direct-sow outdoors

Apr 4 – Apr 18

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 4). 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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