When to plant radicchio in Salt Lake City, Utah

March 31 – April 14

Transplant outdoors · typical Salt Lake City year

Climate basis: NOAA station Salt Lake Triad Ctr, UT (USC00427606), 1 mi (2 km) from downtown Salt Lake City (ZCTA 84111 centroid), elevation 4280 ft, on the 1991–2020 climate normals. Transplant radicchio outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (March 31). One year in ten still freezes after April 19.

Last spring freezeMarch 311-in-10 after Apr 19
First fall freezeNovember 81-in-10 before Oct 23
Frost-free season224 daysmedian at 32°F
Hard freeze, 28°Mar 8Nov 18kills even hardy greens
USDA zone7b5 to 10°F winter low not frost timing

The Salt Lake City year

Transplant outdoorsMar 31 – Apr 14
Direct-sow outdoorsMar 3 – Mar 10
Fall plantingAug 10 – Aug 24
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Apr 19
Radicchio in Salt Lake City · freeze context from Salt Lake Triad Ctr, UT, 1991–2020 normals.

Every method, with its sources

Transplant outdoors

Mar 31 – Apr 14

USU places transplants near the last frost-free date, a point rule that is encoded as a 14-day planting span beginning at the last-freeze anchor. Anchored to the median last spring freeze (Mar 31). Utah State University Extension

Direct-sow outdoors

Mar 3 – Mar 10

USU states seeded radicchio may go in 3-4 weeks before the last frost-free date, and because the source gives an explicit range it is encoded directly as -28 to -21 days rather than expanded to a 14-day span. Anchored to the median last spring freeze (Mar 31). Utah State University Extension

Fall planting

Aug 10 – Aug 24

UMN sows the fall crop about three months before the average first fall frost, taken as a -90 day point and encoded as a 14-day span; USU's fall guidance is not combined here because it is anchored to an anticipated maturity date rather than stated directly against the frost date. Anchored to the median first fall freeze (Nov 8). University of Minnesota Extension

Start seeds indoors

Not calculated

No frost-anchored indoor-start window is published, because UMN gives indoor sowing as Minnesota calendar dates ('early April', and July for fall crops) rather than against a freeze date, and the alternative lead time it offers is measured from the transplant date rather than from an anchor, while USU states only that 5-6 weeks are generally required to grow transplants to set-out size.

Variety assumption: UMN gives radicchio about 60 to 70 days to mature, and USU advises selecting early-maturing cultivars for fall plantings.

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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