USDA zone 9a in Louisiana
USDA plant hardiness zone 9a covers 44 locations across Louisiana (average annual extreme minimum 20 to 25 °F): Alexandria, LA, Alexandria, LA, Amite, LA, Angie, LA, Baton Rouge, LA, Baton Rouge, LA, and 38 more. Average last spring frost across this group ranges February 9 (Garyville) to March 20 (Many), and growing seasons run 234–308 days (Leesville to St. Gabriel) — 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 Merryville, this group's median-season location.
- USDA zone
- 9a20 to 25 °F
- Last frost range
- Feb 9–Mar 20avg, 32°F
- First frost range
- Nov 8–Dec 14avg, 32°F
- Growing season range
- 234–308days
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) |
|---|---|---|---|---|---|
| Alexandria | Woodworth, Forest Hill, McNary, Lecompte | Alexandria 5 Sse | Mar 3 | Nov 22 | 263 |
| Alexandria | Woodworth, Pollock | Alexandria Intl Ap | Mar 2 | Nov 17 | 260 |
| Amite | Independence, Roseland, Tangipahoa | Amite | Mar 7 | Nov 18 | 257 |
| Angie | — | Columbia | Mar 5 | Nov 19 | 262 |
| Baton Rouge | Central, Zachary, Erwinville, Baker, Walker, Brownfields, +2 more | Baton Rouge Ryan Ap | Feb 25 | Nov 26 | 276 |
| Baton Rouge | Shenandoah, Addis, Old Jefferson, Oak Hills Place, Plaquemine, Brusly | Lsu Ben-hur Farm | Feb 28 | Nov 26 | 272 |
| Bogalusa | Franklinton, Sun, Varnado | Bogalusa | Mar 2 | Nov 23 | 265 |
| Bordelonville | Lebeau, Moreauville, Bunkie, Mansura, Turkey Creek, Simmesport, +8 more | Bunkie | Feb 28 | Nov 24 | 270 |
| Bordelonville | Monterey, Jonesville, Harrisonburg | Jonesville Locks | Mar 6 | Nov 22 | 261 |
| Branch | Crowley, Egan, Rayne, Estherwood, Iota | Crowley 2 Ne | Feb 20 | Dec 4 | 291 |
| DeQuincy | Reeves, Gillis | Moss Bluff 2 Nnw | Mar 2 | Nov 25 | 267 |
| Deville | Pineville, Ball, Pollock, Center Point | Alexandria Esler Rgnl Ap | Mar 16 | Nov 8 | 239 |
| Erwinville | New Roads, Jackson, Fordoche, Simmesport, Ventress, Livonia, +2 more | New Roads 5 Ne | Feb 19 | Dec 5 | 292 |
| Eunice | Reddell, Pine Prairie, Mamou, Basile, Chataignier | Eunice | Feb 26 | Nov 27 | 276 |
| Florien | Hornbeck | Hodges Gardens | Mar 3 | Nov 27 | 267 |
| Garyville | Killian, Paulina, Lutcher, Gramercy | Reserve | Feb 9 | Dec 14 | 308 |
| Georgetown | — | Jena | Mar 19 | Nov 12 | 238 |
| Gueydan | — | Lake Arthur 7 Sw | Feb 10 | Dec 11 | 307 |
| Hammond | Killian, Ponchatoula, Natalbany, Livingston, Madisonville, Folsom, +2 more | Hammond 5 E | Mar 8 | Nov 19 | 257 |
| Jennings | Welsh, Egan, Mermentau, Lacassine, Morse, Roanoke | Jennings | Feb 19 | Dec 4 | 292 |
| Kinder | Oakdale, Oberlin, Reeves, Sugartown, Elton, Fenton | Oberlin Fire Twr | Mar 1 | Nov 24 | 267 |
| Lacombe | Slidell, Abita Springs, Sun, Pearl River, Lewisburg | Slidell Ap | Mar 3 | Nov 21 | 263 |
| Lafayette | Broussard, Henderson | Lafayette Rgnl Ap | Feb 13 | Dec 4 | 299 |
| Lafayette | Carencro, Milton, Ossun, Duson, Maurice | Lafayette | Feb 26 | Nov 28 | 279 |
| Lake Charles | Sulphur, Westlake, Iowa | Lake Charles | Feb 14 | Dec 7 | 299 |
| Leesville | Fort Polk North, Simpson, Fort Polk South, Anacoco | Leesville | Mar 20 | Nov 9 | 234 |
| Loreauville | — | Jeanerette 5 Nw | Feb 15 | Dec 3 | 294 |
| Mandeville | Covington, Sun | Covington 4 Nnw | Mar 12 | Nov 18 | 253 |
| Many | Fisher | Many | Mar 20 | Nov 9 | 236 |
| Merryville * | DeRidder, Longville, Newton, Rosepine, Kirbyville, Oretta, +1 more | De Ridder | Mar 1 | Nov 25 | 269 |
| Natchitoches | Montgomery, Clarence, Robeline, Natchez | Natchitoches | Feb 28 | Dec 1 | 275 |
| Opelousas | Carencro, Lawtell, Church Point, Leonville, Grand Coteau, Cankton, +6 more | Grand Coteau | Feb 28 | Nov 23 | 267 |
| Perry | — | Leland Bowman Lock | Feb 17 | Dec 5 | 298 |
| Pineville | — | Alexandria | Feb 27 | Nov 27 | 274 |
| Pitkin | Elizabeth | Elizabeth | Mar 3 | Nov 25 | 268 |
| Pitkin | — | Ft Polk Fullerton Lndg Strip | Mar 1 | Nov 23 | 268 |
| Provencal | — | Peason Ridge Range | Mar 8 | Nov 18 | 258 |
| Rosedale | Addis, Grosse Tete | Brusly 2 W | Feb 28 | Nov 24 | 268 |
| Simpson | Montgomery, Colfax, Dry Prong, Atlanta, Boyce | Boyce 3 Wnw | Mar 2 | Nov 27 | 271 |
| Slaughter | Norwood, Clinton, Wilson, Greensburg, Montpelier, Watson | Clinton 5 Se | Mar 13 | Nov 17 | 251 |
| Slidell | Pearlington | Slidell | Feb 24 | Dec 1 | 281 |
| St. Gabriel | Prairieville, Gonzales, Crescent, White Castle | Carville 2 Sw | Feb 9 | Dec 13 | 308 |
| St. James | Belle Rose, Donaldsonville, Sorrento, Hester, Romeville, French Settlement, +2 more | Donaldsonville 4 Sw | Feb 21 | Dec 5 | 291 |
| Youngsville | Cade, St. Martinville | New Iberia Acadiana Rgnl Ap | Feb 14 | Dec 5 | 298 |
* Merryville 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 (Merryville, representative)
Computed from Merryville's average frost dates — the median-season location in this Louisianazone 9a 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 4 – Jan 18 | Mar 8 – Mar 15 | May 7 – May 27 | — | matures comfortably |
| Pepper | Very tender | Jan 1 – Jan 4 | Mar 15 – Mar 22 | May 14 – Jun 13 | — | matures comfortably |
| Cucumber | Tender | Feb 1 – Feb 8 | Mar 8 – Mar 15 | Apr 27 – May 17 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Mar 8 – Mar 15 | Apr 22 – May 7 | — | matures comfortably |
| Bush bean | Tender | — | Mar 8 – Mar 15 | Apr 27 – May 7 | Sep 26 – Oct 6 | matures comfortably |
| Sweet corn | Tender | — | Mar 1 – Mar 15 | Apr 30 – May 30 | — | matures comfortably |
| Basil | Very tender | Jan 18 – Feb 1 | Mar 8 – Mar 15 | Apr 7 – Apr 22 | — | matures comfortably |
| Lettuce | Half-hardy | Jan 18 – Feb 1 | Feb 1 – Feb 15 | Mar 18 – Apr 2 | Sep 12 – Sep 27 | matures comfortably |
| Pea | Hardy | — | Jan 18 – Feb 1 | Mar 14 – Mar 29 | Sep 2 – Sep 17 | matures comfortably |
| Spinach | Hardy | — | Jan 18 – Feb 1 | Feb 27 – Mar 9 | Sep 22 – Oct 2 | matures comfortably |
| Carrot | Half-hardy | — | Feb 8 – Feb 15 | Apr 9 – Apr 29 | Aug 23 – Sep 12 | matures comfortably |
| Broccoli | Half-hardy | Jan 4 – Jan 18 | Feb 1 – Feb 15 | Mar 28 – Apr 17 | Aug 28 – Sep 17 | matures comfortably |
Which crops fit this growing season
Using Merryville's own 269-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 (Merryville)
From NOAA's 1991–2020 Climate Normals at station USC00162367. 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 | Mar 18 | Apr 9 | Nov 13 | Nov 30 | 240 |
| 32°F (freeze) | Mar 1 | Mar 25 | Nov 25 | Dec 13 | 269 |
| 28°F | Feb 12 | Mar 10 | Dec 7 | Jan 8 | 302 |
| 24°F | Jan 27 | Feb 28 | Dec 30 | Jan 29 | 338 |
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 44 locations is 6,646; Merryville's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 6,625 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 9,986 | cool-season crops (brassicas, greens) |
Hardiness zone 9a in Louisiana
Zone 9a means an average annual extreme minimum winter temperature of about 20 to 25 °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, 9b, 10a.
Explore zone 9a in other states at zone 9a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 9a mean in Louisiana?
- Zone 9a means an average annual extreme minimum winter temperature of 20 to 25 °F — the standard USDA measure of which perennials survive winter. 44 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 9a is the growing season longest?
- St. Gabriel runs the longest season on this page at about 308 days; Leesville is shortest at about 234 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 9a?
- Using Merryville's frost dates (this page's median-season location): start seeds indoors about Jan 4 – Jan 18, then transplant outside about Mar 8 – Mar 15. 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 9a 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 44 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.