Thomaston, GA planting calendar
- USDA zone
- 8b15 to 20 °F
- Last frost
- Mar 23avg, 32°F
- First frost
- Nov 12avg, 32°F
- Growing season
- 234days
Thomaston, Georgia is in USDA plant hardiness zone 8b. Its average last spring frost is around March 23 and the first fall frost around November 12, giving a growing season of about 234 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.
Thomaston planting calendar
Each crop's windows are counted from Thomaston'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 | Jan 26 – Feb 9 | Mar 30 – Apr 6 | May 29 – Jun 18 | — |
| Pepper | Very tender | Jan 12 – Jan 26 | Apr 6 – Apr 13 | Jun 5 – Jul 5 | — |
| Cucumber | Tender | Feb 23 – Mar 2 | Mar 30 – Apr 6 | May 19 – Jun 8 | — |
| Summer squash / zucchini | Tender | — | Mar 30 – Apr 6 | May 14 – May 29 | — |
| Bush bean | Tender | — | Mar 30 – Apr 6 | May 19 – May 29 | Sep 13 – Sep 23 |
| Sweet corn | Tender | — | Mar 23 – Apr 6 | May 22 – Jun 21 | — |
| Basil | Very tender | Feb 9 – Feb 23 | Mar 30 – Apr 6 | Apr 29 – May 14 | — |
| Lettuce | Half-hardy | Feb 9 – Feb 23 | Feb 23 – Mar 9 | Apr 9 – Apr 24 | Aug 30 – Sep 14 |
| Pea | Hardy | — | Feb 9 – Feb 23 | Apr 5 – Apr 20 | Aug 20 – Sep 4 |
| Spinach | Hardy | — | Feb 9 – Feb 23 | Mar 21 – Mar 31 | Sep 9 – Sep 19 |
| Carrot | Half-hardy | — | Mar 2 – Mar 9 | May 1 – May 21 | Aug 10 – Aug 30 |
| Broccoli | Half-hardy | Jan 26 – Feb 9 | Feb 23 – Mar 9 | Apr 19 – May 9 | Aug 15 – Sep 4 |
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 USC00098661. 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 5 | Apr 20 | Nov 1 | Nov 16 | 211 |
| 32°F (freeze) | Mar 23 | Apr 11 | Nov 12 | Nov 28 | 234 |
| 28°F | Mar 10 | Mar 29 | Nov 26 | Dec 18 | 260 |
| 24°F | Feb 24 | Mar 17 | Dec 13 | Jan 8 | 295 |
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) | 5,500 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 8,692 | cool-season crops (brassicas, greens) |
Hardiness zone 8b
Thomaston sits in USDA plant hardiness zone 8b on the 2023 map — meaning its average annual extreme minimum winter temperature is about 15 to 20 °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 8b, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Thomaston?
- Thomaston, Georgia is in USDA plant hardiness zone 8b on the 2023 map (average annual extreme minimum temperature 15 to 20 °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 Thomaston?
- The average (median) last spring frost at 32°F is around March 23, 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 11, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Thomaston?
- The average first fall frost at 32°F is around November 12. That leaves a growing season of about 234 days between the average last spring and first fall frosts.
- When should I start tomatoes in Thomaston?
- Start tomato seeds indoors about Jan 26 – Feb 9 and transplant them outside about Mar 30 – Apr 6, once the danger of frost has passed. Estimated first harvest is around May 29 – Jun 18.
- How long is the growing season in Thomaston?
- About 234 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~March 23) and the average first fall frost (~November 12). 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 USC00098661 (Thomaston 4se, 6.5 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.