Chattanooga, OK planting calendar
- USDA zone
- 8a10 to 15 °F
- Last frost
- Apr 7avg, 32°F
- First frost
- Nov 2avg, 32°F
- Growing season
- 205days
Chattanooga, Oklahoma is in USDA plant hardiness zone 8a. Its average last spring frost is around April 7 and the first fall frost around November 2, giving a growing season of about 205 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.
Chattanooga planting calendar
Each crop's windows are counted from Chattanooga'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 10 – Feb 24 | Apr 14 – Apr 21 | Jun 13 – Jul 3 | — |
| Pepper | Very tender | Jan 27 – Feb 10 | Apr 21 – Apr 28 | Jun 20 – Jul 20 | — |
| Cucumber | Tender | Mar 10 – Mar 17 | Apr 14 – Apr 21 | Jun 3 – Jun 23 | — |
| Summer squash / zucchini | Tender | — | Apr 14 – Apr 21 | May 29 – Jun 13 | — |
| Bush bean | Tender | — | Apr 14 – Apr 21 | Jun 3 – Jun 13 | Sep 3 – Sep 13 |
| Sweet corn | Tender | — | Apr 7 – Apr 21 | Jun 6 – Jul 6 | — |
| Basil | Very tender | Feb 24 – Mar 10 | Apr 14 – Apr 21 | May 14 – May 29 | — |
| Lettuce | Half-hardy | Feb 24 – Mar 10 | Mar 10 – Mar 24 | Apr 24 – May 9 | Aug 20 – Sep 4 |
| Pea | Hardy | — | Feb 24 – Mar 10 | Apr 20 – May 5 | Aug 10 – Aug 25 |
| Spinach | Hardy | — | Feb 24 – Mar 10 | Apr 5 – Apr 15 | Aug 30 – Sep 9 |
| Carrot | Half-hardy | — | Mar 17 – Mar 24 | May 16 – Jun 5 | Jul 31 – Aug 20 |
| Broccoli | Half-hardy | Feb 10 – Feb 24 | Mar 10 – Mar 24 | May 4 – May 24 | Aug 5 – Aug 25 |
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 USC00341706. 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 17 | Apr 30 | Oct 23 | Nov 6 | 188 |
| 32°F (freeze) | Apr 7 | Apr 24 | Nov 2 | Nov 16 | 205 |
| 28°F | Mar 26 | Apr 14 | Nov 9 | Nov 27 | 229 |
| 24°F | Mar 9 | Mar 31 | Nov 21 | Dec 10 | 255 |
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) | 5,356 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 8,208 | cool-season crops (brassicas, greens) |
Hardiness zone 8a
Chattanooga sits in USDA plant hardiness zone 8a on the 2023 map — meaning its average annual extreme minimum winter temperature is about 10 to 15 °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 8a, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Chattanooga?
- Chattanooga, Oklahoma is in USDA plant hardiness zone 8a on the 2023 map (average annual extreme minimum temperature 10 to 15 °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 Chattanooga?
- The average (median) last spring frost at 32°F is around April 7, 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 24, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Chattanooga?
- The average first fall frost at 32°F is around November 2. That leaves a growing season of about 205 days between the average last spring and first fall frosts.
- When should I start tomatoes in Chattanooga?
- Start tomato seeds indoors about Feb 10 – Feb 24 and transplant them outside about Apr 14 – Apr 21, once the danger of frost has passed. Estimated first harvest is around Jun 13 – Jul 3.
- How long is the growing season in Chattanooga?
- About 205 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~April 7) and the average first fall frost (~November 2). 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 USC00341706 (Chattanooga, 2.7 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.