Mobile, AL 36615 planting calendar
- USDA zone
- 9a20 to 25 °F
- Last frost
- Feb 21avg, 32°F
- First frost
- Dec 6avg, 32°F
- Growing season
- 292days
Mobile, Alabama is in USDA plant hardiness zone 9a. Its average last spring frost is around February 21 and the first fall frost around December 6, giving a growing season of about 292 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.
Mobile planting calendar
Each crop's windows are counted from Mobile'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 1 – Jan 10 | Feb 28 – Mar 7 | Apr 29 – May 19 | — |
| Pepper | Very tender | Jan 1 | Mar 7 – Mar 14 | May 6 – Jun 5 | — |
| Cucumber | Tender | Jan 24 – Jan 31 | Feb 28 – Mar 7 | Apr 19 – May 9 | — |
| Summer squash / zucchini | Tender | — | Feb 28 – Mar 7 | Apr 14 – Apr 29 | — |
| Bush bean | Tender | — | Feb 28 – Mar 7 | Apr 19 – Apr 29 | Oct 7 – Oct 17 |
| Sweet corn | Tender | — | Feb 21 – Mar 7 | Apr 22 – May 22 | — |
| Basil | Very tender | Jan 10 – Jan 24 | Feb 28 – Mar 7 | Mar 30 – Apr 14 | — |
| Lettuce | Half-hardy | Jan 10 – Jan 24 | Jan 24 – Feb 7 | Mar 10 – Mar 25 | Sep 23 – Oct 8 |
| Pea | Hardy | — | Jan 10 – Jan 24 | Mar 6 – Mar 21 | Sep 13 – Sep 28 |
| Spinach | Hardy | — | Jan 10 – Jan 24 | Feb 19 – Mar 1 | Oct 3 – Oct 13 |
| Carrot | Half-hardy | — | Jan 31 – Feb 7 | Apr 1 – Apr 21 | Sep 3 – Sep 23 |
| Broccoli | Half-hardy | Jan 1 – Jan 10 | Jan 24 – Feb 7 | Mar 20 – Apr 9 | Sep 8 – Sep 28 |
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 USW00013838. 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 | Mar 6 | Mar 25 | Nov 22 | Dec 13 | 264 |
| 32°F (freeze) | Feb 21 | Mar 15 | Dec 6 | Jan 5 | 292 |
| 28°F | Feb 2 | Mar 6 | Dec 30 | Jan 30 | 326 |
| 24°F | Jan 22 | Feb 23 | Jan 9 | Feb 6 | 359 |
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) | 7,192 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 10,672 | cool-season crops (brassicas, greens) |
Hardiness zone 9a
Mobile sits in USDA plant hardiness zone 9a on the 2023 map — meaning its average annual extreme minimum winter temperature is about 20 to 25 °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 9a, or see all USDA hardiness zones.
Frequently asked questions
- What USDA hardiness zone is Mobile?
- Mobile, Alabama is in USDA plant hardiness zone 9a on the 2023 map (average annual extreme minimum temperature 20 to 25 °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 Mobile?
- The average (median) last spring frost at 32°F is around February 21, from NOAA's 1991–2020 climate normals at the nearest reporting station. Roughly one year in ten the last frost is as late as March 15, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Mobile?
- The average first fall frost at 32°F is around December 6. That leaves a growing season of about 292 days between the average last spring and first fall frosts.
- When should I start tomatoes in Mobile?
- Start tomato seeds indoors about Jan 1 – Jan 10 and transplant them outside about Feb 28 – Mar 7, once the danger of frost has passed. Estimated first harvest is around Apr 29 – May 19.
- How long is the growing season in Mobile?
- About 292 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~February 21) and the average first fall frost (~December 6). 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 USW00013838 (Mobile Dwtn Ap, 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.