USDA zone 10a in Louisiana
USDA plant hardiness zone 10a covers 3 locations across Louisiana (average annual extreme minimum 30 to 35 °F): Empire, LA, Grand Isle, LA, Triumph, LA. Average last spring frost across this group ranges January 23 (Triumph) to February 8 (Grand Isle), and growing seasons run 311–357 days (Grand Isle to Triumph) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Louisiana location's own frost dates; the printable planting calendar uses Empire, this group's median-season location.
- USDA zone
- 10a30 to 35 °F
- Last frost range
- Jan 23–Feb 8avg, 32°F
- First frost range
- Jan 4–Dec 19avg, 32°F
- Growing season range
- 311–357days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Empire * | — | Buras | Jan 25 | Jan 4 | 346 |
| Grand Isle | Golden Meadow | Galliano | Feb 8 | Dec 19 | 311 |
| Triumph | Boothville, Venice | Boothville Asos | Jan 23 | Jan 9 | 357 |
* Empire is this group's median-season location — the calendar below is computed from its data.
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.
Planting calendar (Empire, representative)
Computed from Empire's average frost dates — the median-season location in this Louisianazone 10a group. 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 — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Jan 1 | Feb 1 – Feb 8 | Apr 2 – Apr 22 | — | matures comfortably |
| Pepper | Very tender | Jan 1 | Feb 8 – Feb 15 | Apr 9 – May 9 | — | matures comfortably |
| Cucumber | Tender | Jan 1 – Jan 4 | Feb 1 – Feb 8 | Mar 23 – Apr 12 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Feb 1 – Feb 8 | Mar 18 – Apr 2 | — | matures comfortably |
| Bush bean | Tender | — | Feb 1 – Feb 8 | Mar 23 – Apr 2 | — | matures comfortably |
| Sweet corn | Tender | — | Jan 25 – Feb 8 | Mar 26 – Apr 25 | — | matures comfortably |
| Basil | Very tender | Jan 1 | Feb 1 – Feb 8 | Mar 3 – Mar 18 | — | matures comfortably |
| Lettuce | Half-hardy | Jan 1 | Jan 1 – Jan 11 | Feb 15 – Mar 2 | — | matures comfortably |
| Pea | Hardy | — | Jan 1 | Feb 25 – Mar 12 | — | matures comfortably |
| Spinach | Hardy | — | Jan 1 | Feb 10 – Feb 20 | — | matures comfortably |
| Carrot | Half-hardy | — | Jan 4 – Jan 11 | Mar 5 – Mar 25 | — | matures comfortably |
| Broccoli | Half-hardy | Jan 1 | Jan 1 – Jan 11 | Feb 25 – Mar 17 | — | matures comfortably |
Which crops fit this growing season
Using Empire's own 346-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Empire)
From NOAA's 1991–2020 Climate Normals at station USC00161292. 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 — 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 | Feb 5 | Mar 9 | Dec 25 | Jan 17 | 316 |
| 32°F (freeze) | Jan 25 | Feb 21 | Jan 4 | Jan 29 | 346 |
| 28°F | Jan 17 | Feb 5 | Jan 9 | Feb 1 | 365 |
| 24°F | Jan 13 | Feb 2 | Jan 13 | Feb 1 | 365 |
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. This group's median GDD (base 50°F) across all 3 locations is 7,513; Empire's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 7,513 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 11,073 | cool-season crops (brassicas, greens) |
Hardiness zone 10a in Louisiana
Zone 10a means an average annual extreme minimum winter temperature of about 30 to 35 °F on the USDA's 2023 map — the number that 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. Louisiana spans 4 hardiness zones in this dataset — see all Louisiana locations for the full range, including zones8b, 9a, 9b.
Explore zone 10a in other states at zone 10a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 10a mean in Louisiana?
- Zone 10a means an average annual extreme minimum winter temperature of 30 to 35 °F — the standard USDA measure of which perennials survive winter. 3 locations in Louisiana fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Louisiana's zone 10a is the growing season longest?
- Triumph runs the longest season on this page at about 357 days; Grand Isle is shortest at about 311 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Louisiana's zone 10a?
- Using Empire's frost dates (this page's median-season location): start seeds indoors about Jan 1, then transplant outside about Feb 1 – Feb 8. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Louisiana's zone 10a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 3 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each 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.