When to plant rhubarb in San Antonio, Texas

January 14 – January 28

Transplant outdoors · typical San Antonio year

Climate basis: NOAA station San Antonio Incarnate Word, TX (USC00417947), 3 mi (5 km) from downtown San Antonio (ZCTA 78205 centroid), elevation 700 ft, on the 1991–2020 climate normals. Transplant rhubarb outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (February 25). One year in ten still freezes after March 19.

Last spring freezeFebruary 251-in-10 after Mar 19
First fall freezeNovember 281-in-10 before Nov 7
Frost-free season277 daysmedian at 32°F
Hard freeze, 28°Feb 5Dec 15kills even hardy greens
USDA zone9a20 to 25°F winter low not frost timing

The San Antonio year

Transplant outdoorsJan 14 – Jan 28
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Mar 19
Rhubarb in San Antonio · freeze context from San Antonio Incarnate Word, TX, 1991–2020 normals.

Every method, with its sources

Transplant outdoors

Jan 14 – Jan 28

Purdue Extension HO-186-W Table 1 lists rhubarb in the group headed "Hardy (tolerates hard frost)" with the instruction "plant 4-6 weeks before last spring frost (see Figure 1)" and footnotes it as typically vegetatively propagated, so the source's own 4-6 week range is used directly as the window for setting out dormant crowns rather than seed; the University of Minnesota rhubarb guide was re-checked and anchors only indoor seed starting to the last frost, so it supplied no competing crown-planting date to reconcile against. Anchored to the median last spring freeze (Feb 25). Purdue University Extension, Department of Horticulture and Landscape Architecture

Start seeds indoors

Not calculated

Rhubarb is planted from crowns or divisions, and although the Minnesota guide does say to start seed indoors six weeks before the last frost, seed-grown plants push the first harvest to the third season and are not the planting path this window times.

Direct-sow outdoors

Not calculated

Purdue Table 1 footnotes rhubarb as typically vegetatively propagated and publishes no separate direct-seeding date for it.

Fall planting

Not calculated

No source-backed fall planting rule exists for this crop in the registry, so no fall window is calculated.

Variety assumption: A long-lived perennial planted from crowns or divisions: Minnesota advises waiting until the second season before harvesting (the third season if started from seed), with the harvest season running until the end of June.

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 (1)

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