Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Saint Louis, MO

Saint Louis, MO is in USDA zone 7a across its 66 ZIP codes. The median last spring frost is April 1 and the first fall frost November 4.

Saint Louis on the zone map

Outlined: its 46 ZIP code areas · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone7a0 to 5 °F

ZIP codes66

Last frostApr 1

First frostNov 4

Growing season218 days

7a 66 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Saint Louis, MO

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 1median — 50% chance of a later frost

Safe for tender plantsApril 18only 10% chance of frost after

First fall frostNovember 4median — 10% chance by Oct 24

Growing season218 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 22 and returns around November 15.

From the NOAA station St Louis Sci Center, MO, elevation 515 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in Saint Louis

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 18 – Mar 4

SpinachSow outdoors · Feb 18 – Mar 11

Broccoli, cabbageStart indoors · Jan 21 – Feb 4

Broccoli, cabbageTransplant · Mar 11 – Mar 25

Onion setsPlant outdoors · Mar 4 – Mar 18

PotatoesPlant outdoors · Mar 11 – Mar 25

LettuceSow outdoors · Mar 4 – Mar 18

Carrots, beetsSow outdoors · Mar 11 – Mar 25

TomatoesStart indoors · Feb 4 – Feb 18

TomatoesTransplant · Apr 8 – Apr 22

Peppers, eggplantStart indoors · Jan 21 – Feb 4

Peppers, eggplantTransplant · Apr 15 – Apr 29

BeansSow outdoors · Apr 8 – Apr 22

Sweet cornSow outdoors · Apr 8 – Apr 22

Cucumbers, squashSow outdoors · Apr 8 – Apr 22

Fall lettuce, spinachSow outdoors · Sep 9 – Sep 23

GarlicPlant cloves · Oct 21 – Nov 25

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 1) and first fall frost (Nov 4) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 63112 came on Mar 1 — 11 days earlier than the 1991–2020 average (Mar 12).

average
Mar 122026
Mar 1

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 7a in Missouri

540 plants native to the lower 48 states, recorded in Missouri, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Saint Louis, MO.

Soil in Saint Louis, MO

The soil mapped at the center of ZIP 63112 is Vandeventer — silt loam, well drained. Much of the area is built over (urban land); this is the natural soil underneath.

TextureSilt loama good balance for most vegetables

pH7.1neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.5%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Urban land-Vandeventer-Shaw complex, 1 to 3 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 63112; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Saint Louis, MO

Summer high90 °Faverage high, July

Winter low25 °Faverage low, January

Hot days47days a year at 90 °F or more

Freezing nights79nights a year at 32 °F or less

Growing degree days4,703base 50 °F — the season’s usable heat

Longest day14 h 52 mindaylight on June 21

Shortest day9 h 28 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation43.9 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: St Louis Sci Center, MO (2 mi away); precipitation: St Louis Sci Center, MO (2 mi away). Daylight is calculated from latitude.

Planting zone for Saint Louis, MO

Saint Louis on the zone map

Frost forecast — next 7 nights

Frost dates in Saint Louis, MO

When to plant vegetables in Saint Louis

When spring arrived in 2026

Native plants for zone 7a in Missouri

Trees 72

Shrubs 85

Wildflowers & perennials 195

Grasses 163

Vines 14

Soil in Saint Louis, MO

Climate in Saint Louis, MO

Average high and low, by month

Precipitation by month inches

ZIP codes in Saint Louis

Questions about Saint Louis