Jasper, AL planting calendar
- USDA zone
- 8a10 to 15 °F
- Last frost
- Mar 30avg, 32°F
- First frost
- Nov 4avg, 32°F
- Growing season
- 220days
Jasper, Alabama is in USDA plant hardiness zone 8a. Its average last spring frost is around March 30 and the first fall frost around November 4, giving a growing season of about 220 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.
Jasper planting calendar
Each crop's windows are counted from Jasper'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 2 – Feb 16 | Apr 6 – Apr 13 | Jun 5 – Jun 25 | — |
| Pepper | Very tender | Jan 19 – Feb 2 | Apr 13 – Apr 20 | Jun 12 – Jul 12 | — |
| Cucumber | Tender | Mar 2 – Mar 9 | Apr 6 – Apr 13 | May 26 – Jun 15 | — |
| Summer squash / zucchini | Tender | — | Apr 6 – Apr 13 | May 21 – Jun 5 | — |
| Bush bean | Tender | — | Apr 6 – Apr 13 | May 26 – Jun 5 | Sep 5 – Sep 15 |
| Sweet corn | Tender | — | Mar 30 – Apr 13 | May 29 – Jun 28 | — |
| Basil | Very tender | Feb 16 – Mar 2 | Apr 6 – Apr 13 | May 6 – May 21 | — |
| Lettuce | Half-hardy | Feb 16 – Mar 2 | Mar 2 – Mar 16 | Apr 16 – May 1 | Aug 22 – Sep 6 |
| Pea | Hardy | — | Feb 16 – Mar 2 | Apr 12 – Apr 27 | Aug 12 – Aug 27 |
| Spinach | Hardy | — | Feb 16 – Mar 2 | Mar 28 – Apr 7 | Sep 1 – Sep 11 |
| Carrot | Half-hardy | — | Mar 9 – Mar 16 | May 8 – May 28 | Aug 2 – Aug 22 |
| Broccoli | Half-hardy | Feb 2 – Feb 16 | Mar 2 – Mar 16 | Apr 26 – May 16 | Aug 7 – Aug 27 |
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 USC00014226. 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 11 | Apr 29 | Oct 25 | Nov 6 | 198 |
| 32°F (freeze) | Mar 30 | Apr 16 | Nov 4 | Nov 19 | 220 |
| 28°F | Mar 14 | Apr 3 | Nov 15 | Dec 4 | 247 |
| 24°F | Feb 28 | Mar 19 | Nov 30 | Dec 23 | 275 |
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) | 5,028 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 7,987 | cool-season crops (brassicas, greens) |
Hardiness zone 8a
Jasper 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 Jasper?
- Jasper, Alabama 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 Jasper?
- The average (median) last spring frost at 32°F is around March 30, 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 16, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Jasper?
- The average first fall frost at 32°F is around November 4. That leaves a growing season of about 220 days between the average last spring and first fall frosts.
- When should I start tomatoes in Jasper?
- Start tomato seeds indoors about Feb 2 – Feb 16 and transplant them outside about Apr 6 – Apr 13, once the danger of frost has passed. Estimated first harvest is around Jun 5 – Jun 25.
- How long is the growing season in Jasper?
- About 220 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~March 30) and the average first fall frost (~November 4). 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 USC00014226 (Jasper, 3.7 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.