Mandeville, LA planting calendar
- USDA zone
- 9a20 to 25 °F
- Last frost
- Mar 12avg, 32°F
- First frost
- Nov 18avg, 32°F
- Growing season
- 253days
Mandeville, Louisiana is in USDA plant hardiness zone 9a. Its average last spring frost is around March 12 and the first fall frost around November 18, giving a growing season of about 253 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.
Mandeville planting calendar
Each crop's windows are counted from Mandeville'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 15 – Jan 29 | Mar 19 – Mar 26 | May 18 – Jun 7 | — |
| Pepper | Very tender | Jan 1 – Jan 15 | Mar 26 – Apr 2 | May 25 – Jun 24 | — |
| Cucumber | Tender | Feb 12 – Feb 19 | Mar 19 – Mar 26 | May 8 – May 28 | — |
| Summer squash / zucchini | Tender | — | Mar 19 – Mar 26 | May 3 – May 18 | — |
| Bush bean | Tender | — | Mar 19 – Mar 26 | May 8 – May 18 | Sep 19 – Sep 29 |
| Sweet corn | Tender | — | Mar 12 – Mar 26 | May 11 – Jun 10 | — |
| Basil | Very tender | Jan 29 – Feb 12 | Mar 19 – Mar 26 | Apr 18 – May 3 | — |
| Lettuce | Half-hardy | Jan 29 – Feb 12 | Feb 12 – Feb 26 | Mar 29 – Apr 13 | Sep 5 – Sep 20 |
| Pea | Hardy | — | Jan 29 – Feb 12 | Mar 25 – Apr 9 | Aug 26 – Sep 10 |
| Spinach | Hardy | — | Jan 29 – Feb 12 | Mar 10 – Mar 20 | Sep 15 – Sep 25 |
| Carrot | Half-hardy | — | Feb 19 – Feb 26 | Apr 20 – May 10 | Aug 16 – Sep 5 |
| Broccoli | Half-hardy | Jan 15 – Jan 29 | Feb 12 – Feb 26 | Apr 8 – Apr 28 | Aug 21 – Sep 10 |
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 USC00162151. 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 27 | Apr 15 | Nov 7 | Nov 25 | 227 |
| 32°F (freeze) | Mar 12 | Apr 3 | Nov 18 | Dec 12 | 253 |
| 28°F | Feb 19 | Mar 17 | Dec 3 | Jan 6 | 290 |
| 24°F | Jan 31 | Mar 4 | Jan 1 | Jan 31 | 330 |
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) | 6,473 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 9,888 | cool-season crops (brassicas, greens) |
Hardiness zone 9a
Mandeville 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 Mandeville?
- Mandeville, Louisiana 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 Mandeville?
- The average (median) last spring frost at 32°F is around March 12, 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 3, so wait until then before setting out frost-tender plants if you want to be safe.
- When is the first fall frost in Mandeville?
- The average first fall frost at 32°F is around November 18. That leaves a growing season of about 253 days between the average last spring and first fall frosts.
- When should I start tomatoes in Mandeville?
- Start tomato seeds indoors about Jan 15 – Jan 29 and transplant them outside about Mar 19 – Mar 26, once the danger of frost has passed. Estimated first harvest is around May 18 – Jun 7.
- How long is the growing season in Mandeville?
- About 253 days at the 32°F threshold (NOAA 1991–2020, median) — the span between the average last spring frost (~March 12) and the average first fall frost (~November 18). 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 USC00162151 (Covington 4 Nnw, 0.2 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.