When to plant spinach in San Antonio, Texas
January 14 – February 4
Transplant outdoors · typical San Antonio yearClimate 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 spinach 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.
The San Antonio year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to Mar 19
Every method, with its sources
Transplant outdoors
Jan 14 – Feb 4UNH: safe to set out 3–6 weeks before the last frost. Anchored to the median last spring freeze (Feb 25). University of New Hampshire Extension
Direct-sow outdoors
Jan 26 – Feb 9Purdue: hardy — 4–6 weeks before the last frost; Penn State's earliest sowing Apr 1 (−30 days) is the later start and is used. Anchored to the median last spring freeze (Feb 25). Penn State Extension (York County Master Gardeners) · Purdue University Extension
Fall planting
Oct 3 – Oct 31Purdue Table 2: plant fall spinach at least 4–8 weeks before the first fall frost. Anchored to the median first fall freeze (Nov 28). Purdue University Extension
Variety assumption: Assumes an average savoy/smooth variety (about 40–50 days; Penn State lists 50).
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.
Crop rule sources (3)
- Penn State Extension (York County Master Gardeners): Vegetable Seed Planting Guide (accessed 2026-07-24)Earliest/latest sowing dates for a May 1 last-frost / Oct 1 first-frost baseline; offsets derived by date difference from May 1. Also days-to-maturity figures.
- Purdue University Extension: Indiana Vegetable Planting Calendar (HO-186-W) (accessed 2026-07-24)Hardiness classes: hardy = plant 4-6 wk before last spring frost; semi-hardy = 2-4 wk before; tender = after average last frost; very tender = at least 2 wk after. Table 2: fall planting at least 4-8 wk before first fall frost.
- University of New Hampshire Extension: Growing Vegetables: When to Plant Your Vegetable Garden [fact sheet] (accessed 2026-07-24)Per-crop 'time from seed to transplant' and 'safe to set out in garden' relative to last frost.