Iberia, MO planting calendar
- USDA zone
- 6b−5 to 0 °F
- Last frost
- Apr 8avg, 32°F
- First frost
- Oct 28avg, 32°F
- Growing season
- 200days
Iberia, Missouri is in USDA plant hardiness zone 6b. Its average last spring frost is around April 8 and the first fall frost around October 28, giving a growing season of about 200 days (NOAA 1991–2020 normals, 32°F, median). Start tender crops like tomatoes and peppers indoors weeks before the last frost and set them out afterward; sow hardy crops such as peas, spinach, and lettuce before it. The planner below turns those frost dates into a printable per-crop planting calendar.
Iberia planting calendar
Each crop's windows are counted from Iberia's average frost dates. 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.
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting |
|---|---|---|---|---|---|
| Tomato | Tender | Feb 11 – Feb 25 | Apr 15 – Apr 22 | Jun 14 – Jul 4 | — |
| Pepper | Very tender | Jan 28 – Feb 11 | Apr 22 – Apr 29 | Jun 21 – Jul 21 | — |
| Cucumber | Tender | Mar 11 – Mar 18 | Apr 15 – Apr 22 | Jun 4 – Jun 24 | — |
| Summer squash / zucchini | Tender | — | Apr 15 – Apr 22 | May 30 – Jun 14 | — |
| Bush bean | Tender | — | Apr 15 – Apr 22 | Jun 4 – Jun 14 | Aug 29 – Sep 8 |
| Sweet corn | Tender | — | Apr 8 – Apr 22 | Jun 7 – Jul 7 | — |
| Basil | Very tender | Feb 25 – Mar 11 | Apr 15 – Apr 22 | May 15 – May 30 | — |
| Lettuce | Half-hardy | Feb 25 – Mar 11 | Mar 11 – Mar 25 | Apr 25 – May 10 | Aug 15 – Aug 30 |
| Pea | Hardy | — | Feb 25 – Mar 11 | Apr 21 – May 6 | Aug 5 – Aug 20 |
| Spinach | Hardy | — | Feb 25 – Mar 11 | Apr 6 – Apr 16 | Aug 25 – Sep 4 |
| Carrot | Half-hardy | — | Mar 18 – Mar 25 | May 17 – Jun 6 | Jul 26 – Aug 15 |
| Broccoli | Half-hardy | Feb 11 – Feb 25 | Mar 11 – Mar 25 | May 5 – May 25 | Jul 31 – Aug 20 |
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.
Frost & freeze dates
From NOAA's 1991–2020 Climate Normals at station USC00234136. 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 (p10 for spring, p90 for fall) — 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 22 | May 7 | Oct 18 | Oct 30 | 177 |
| 32°F (freeze) | Apr 8 | Apr 26 | Oct 28 | Nov 9 | 200 |
| 28°F | Mar 30 | Apr 14 | Nov 6 | Nov 22 | 221 |
| 24°F | Mar 18 | Apr 3 | Nov 16 | Dec 5 | 242 |
32°F is the standard "freeze" line that damages tender crops; lighter 36°F frost can nip the most cold-sensitive plants, while hardy crops shrug off light frost down toward 28°F. Use the threshold that matches what you are protecting.
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. Warm-season crops need a long, warm GDD total; a short, cool GDD total favors greens and brassicas.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 4,024 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 6,530 | cool-season crops (brassicas, greens) |
Hardiness zone 6b
Iberia sits in USDA plant hardiness zone 6b on the 2023 map — meaning its average annual extreme minimum winter temperature is about −5 to 0 °F. That number 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.
Explore more places in zone 6b, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Iberia?
- Iberia, Missouri is in USDA plant hardiness zone 6b on the 2023 map (average annual extreme minimum temperature −5 to 0 °F) — from the USDA Plant Hardiness Zone Map 2023, matched to this location's ZIP. See the methodology page for sources.
- When is the last frost in Iberia?
- The average (median) last spring frost at 32°F is around April 8, from NOAA's 1991–2020 climate normals at the nearest reporting station. Roughly one year in ten the last frost is as late as April 26, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Iberia?
- The average first fall frost at 32°F is around October 28. That leaves a growing season of about 200 days between the average last spring and first fall frosts.
- When should I start tomatoes in Iberia?
- Start tomato seeds indoors about Feb 11 – Feb 25 and transplant them outside about Apr 15 – Apr 22, once the danger of frost has passed. Estimated first harvest is around Jun 14 – Jul 4.
- How long is the growing season in Iberia?
- About 200 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~April 8) and the average first fall frost (~October 28). Cold-hardy crops extend usable time at both ends; frost-tender crops fit inside it.
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020 for station USC00234136 (Iberia, 0.5 km away). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to this 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.