When to plant beets in St. Louis, Missouri
March 4 – March 18
Direct-sow outdoors · typical St. Louis yearClimate basis: NOAA station St Louis Sci Ctr, MO (USC00237452), 4 mi (7 km) from downtown St. Louis (ZCTA 63101 centroid), elevation 515 ft, on the 1991–2020 climate normals. Direct-sow beets from approximately the dates above, anchored to the median last spring 32°F freeze (April 1). One year in ten still freezes after April 18.
The St. Louis year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to Apr 18
Every method, with its sources
Direct-sow outdoors
Mar 4 – Mar 18Purdue: semi-hardy — 2–4 weeks before the last frost. Penn State sows from Apr 1 (−30) and UNH keys to 45°F soil; the later Purdue range is used. Anchored to the median last spring freeze (Apr 1). Purdue University Extension · Penn State Extension (York County Master Gardeners) · University of New Hampshire Extension
Fall planting
Sep 9 – Oct 7Purdue Table 2: plant fall beets at least 4–8 weeks before the first fall frost, allowing for days to maturity. Anchored to the median first fall freeze (Nov 4). Purdue University Extension
Variety assumption: Assumes an average round variety (about 55–70 days; Penn State lists 70).
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)
- 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.
- 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.
- 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.