When to plant in St. Louis, MO
USDA Zone 7aEverything below — frost dates, hardiness zone, and what to plant when in St. Louis, Missouri — is derived from the closest NOAA station with complete climate normals.
In zone 7a, St. Louis supports a wide range of perennials year-round; the frost dates above are what set your annual vegetable timing.
Frost probability
ST LOUIS SCI CTR · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are St. Louis’s own odds, recorded at ST LOUIS SCI CTR.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 27 | Apr 12 | Mar 27 | Oct 15 | Oct 26 | Nov 7 |
| 32°F | Apr 18 | Apr 1 | Mar 14 | Oct 24 | Nov 4 | Nov 21 |
| 28°F | Apr 7 | Mar 22 | Mar 5 | Nov 2 | Nov 15 | Dec 4 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in St. Louis, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 10 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
St. Louis planting FAQ
When is the last spring frost in St. Louis, MO?
St. Louis's average last spring frost falls near April 1 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in St. Louis, MO?
Expect St. Louis's first fall frost near November 4 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is St. Louis in?
St. Louis is in USDA hardiness zone 7a. In zone 7a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in St. Louis?
St. Louis has about 217 frost-free days — a long growing season — between the average last spring frost (April 1) and first fall frost (November 4).
When should I plant tomatoes in St. Louis?
For St. Louis, sow tomatoes indoors about February 4–February 18 and move the seedlings out around April 8, after the last spring frost.
Never miss a window in St. Louis
An email when it’s time to start seeds, transplant, and sow — timed to St. Louis’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Clayton · 7 km
- University City · 8 km
- Jennings · 10 km
- East St. Louis · 10 km
- Cahokia Heights · 11 km
- Webster Groves · 11 km
- Lemay · 12 km
- Affton · 12 km
Frost dates recorded at ST LOUIS SCI CTR, 2 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in St. Louis, MO — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00237452. Retrieved from https://blissgarden.com/missouri/st-louis.