USDA zone 5b in Missouri
USDA plant hardiness zone 5b covers 9 locations across Missouri (average annual extreme minimum −15 to −10 °F): Grant, MO, Green, MO, Maryville, MO, Princeton, MO, Ravenwood, MO, Ridgeway, MO, and 3 more. Average last spring frost across this group ranges April 16 (Ridgeway) to April 26 (Green), and growing seasons run 167–186 days (Rock Port to Unionville) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Missouri location's own frost dates; the printable planting calendar uses Tarkio, this group's median-season location.
- USDA zone
- 5b−15 to −10 °F
- Last frost range
- Apr 16–Apr 26avg, 32°F
- First frost range
- Oct 10–Oct 22avg, 32°F
- Growing season range
- 167–186days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Grant | Worth | Grant City | Apr 24 | Oct 14 | 172 |
| Green | — | Green City 5n | Apr 26 | Oct 14 | 169 |
| Maryville | Burlington Junction, Hopkins, Skidmore, Parnell, Pickering | Maryville 2e | Apr 19 | Oct 17 | 180 |
| Princeton | Cainsville, Mercer, Newtown, Lucerne | Princeton | Apr 25 | Oct 15 | 174 |
| Ravenwood | Gentry | Conception | Apr 17 | Oct 20 | 184 |
| Ridgeway | New Hampton, Denver | Bethany | Apr 16 | Oct 22 | 186 |
| Rock Port | Auburn, Brownville, Peru, Fairfax, Brock, Nemaha, +1 more | Auburn 5 Ese | Apr 24 | Oct 10 | 167 |
| Tarkio * | — | Tarkio | Apr 19 | Oct 15 | 177 |
| Unionville | Cincinnati, Livonia, Pollock | Unionville | Apr 17 | Oct 22 | 186 |
* Tarkio is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Tarkio, representative)
Computed from Tarkio's average frost dates — the median-season location in this Missourizone 5b group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Feb 22 – Mar 8 | Apr 26 – May 3 | Jun 25 – Jul 15 | — | matures comfortably |
| Pepper | Very tender | Feb 8 – Feb 22 | May 3 – May 10 | Jul 2 – Aug 1 | — | matures comfortably |
| Cucumber | Tender | Mar 22 – Mar 29 | Apr 26 – May 3 | Jun 15 – Jul 5 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 26 – May 3 | Jun 10 – Jun 25 | — | matures comfortably |
| Bush bean | Tender | — | Apr 26 – May 3 | Jun 15 – Jun 25 | Aug 16 – Aug 26 | matures comfortably |
| Sweet corn | Tender | — | Apr 19 – May 3 | Jun 18 – Jul 18 | — | matures comfortably |
| Basil | Very tender | Mar 8 – Mar 22 | Apr 26 – May 3 | May 26 – Jun 10 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 8 – Mar 22 | Mar 22 – Apr 5 | May 6 – May 21 | Aug 2 – Aug 17 | matures comfortably |
| Pea | Hardy | — | Mar 8 – Mar 22 | May 2 – May 17 | Jul 23 – Aug 7 | matures comfortably |
| Spinach | Hardy | — | Mar 8 – Mar 22 | Apr 17 – Apr 27 | Aug 12 – Aug 22 | matures comfortably |
| Carrot | Half-hardy | — | Mar 29 – Apr 5 | May 28 – Jun 17 | Jul 13 – Aug 2 | matures comfortably |
| Broccoli | Half-hardy | Feb 22 – Mar 8 | Mar 22 – Apr 5 | May 16 – Jun 5 | Jul 18 – Aug 7 | matures comfortably |
Which crops fit this growing season
Using Tarkio's own 177-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Tarkio)
From NOAA's 1991–2020 Climate Normals at station USW00014945. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Apr 30 | May 13 | Oct 5 | Oct 17 | 159 |
| 32°F (freeze) | Apr 19 | May 4 | Oct 15 | Oct 27 | 177 |
| 28°F | Apr 9 | Apr 25 | Oct 25 | Nov 7 | 198 |
| 24°F | Mar 31 | Apr 16 | Nov 2 | Nov 19 | 217 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 9 locations is 3,402; Tarkio's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 3,402 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 5,611 | cool-season crops (brassicas, greens) |
Hardiness zone 5b in Missouri
Zone 5b means an average annual extreme minimum winter temperature of about −15 to −10 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Missouri spans 6 hardiness zones in this dataset — see all Missouri locations for the full range, including zones6a, 6b, 7a, 7b, 8a.
Explore zone 5b in other states at zone 5b, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 5b mean in Missouri?
- Zone 5b means an average annual extreme minimum winter temperature of −15 to −10 °F — the standard USDA measure of which perennials survive winter. 9 locations in Missouri fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Missouri's zone 5b is the growing season longest?
- Unionville runs the longest season on this page at about 186 days; Rock Port is shortest at about 167 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Missouri's zone 5b?
- Using Tarkio's frost dates (this page's median-season location): start seeds indoors about Feb 22 – Mar 8, then transplant outside about Apr 26 – May 3. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Missouri's zone 5b have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 9 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.