What Planting Zones Are in Louisiana?
Louisiana spans USDA hardiness zones 8b to 10a, where the average coldest winter night ranges from 15 °F to 35 °F (−9.4 °C to 1.7 °C). Zone 9a covers the most ZIP codes, 48%, and zones 8b to 9b together cover 99% of the state.
Bars show each zone's share of the 710 Louisiana ZIP codes in the official 2023 USDA ZIP code table; select a zone for its temperatures and hardy plants.
What Hardiness Zone Are Louisiana Cities In?
New Orleans is in zone 9b, Baton Rouge is in zone 9a, Shreveport is in zone 8b and Lafayette is in zone 9a. The table lists the zone, winter low and average frost dates for 18 Louisiana cities, using the ZIP code nearest each city center.
| City | ZIP | Zone | Winter low | Last frost | First frost |
|---|---|---|---|---|---|
| New Orleans | 70128 | 9b | 25 °F to 30 °F | Jan 22 | Jan 5 |
| Baton Rouge | 70806 | 9a | 20 °F to 25 °F | Feb 25 | Nov 26 |
| Shreveport | 71109 | 8b | 15 °F to 20 °F | Mar 6 | Nov 19 |
| Lafayette | 70503 | 9a | 20 °F to 25 °F | Feb 26 | Nov 28 |
| Lake Charles | 70601 | 9a | 20 °F to 25 °F | Feb 14 | Dec 7 |
| Kenner | 70065 | 9b | 25 °F to 30 °F | Jan 30 | Dec 31 |
| Bossier City | 71110 | 8b | 15 °F to 20 °F | Mar 6 | Nov 18 |
| Monroe | 71212 | 8b | 15 °F to 20 °F | Mar 8 | Nov 15 |
| Alexandria | 71301 | 9a | 20 °F to 25 °F | Mar 3 | Nov 22 |
| Houma | 70364 | 9b | 25 °F to 30 °F | Feb 5 | Dec 17 |
| Slidell | 70458 | 9a | 20 °F to 25 °F | Feb 24 | Dec 1 |
| New Iberia | 70560 | 9b | 25 °F to 30 °F | Feb 10 | Dec 11 |
| Hammond | 70402 | 9a | 20 °F to 25 °F | Mar 8 | Nov 19 |
| Ruston | 71272 | 8b | 15 °F to 20 °F | Mar 11 | Nov 16 |
| Zachary | 70791 | 9a | 20 °F to 25 °F | Feb 25 | Nov 26 |
| Natchitoches | 71457 | 9a | 20 °F to 25 °F | Feb 28 | Dec 1 |
| Thibodaux | 70310 | 9b | 25 °F to 30 °F | Feb 5 | Dec 14 |
| Opelousas | 70570 | 9a | 20 °F to 25 °F | Feb 28 | Nov 23 |
Zone: 2023 USDA ZIP code table for the ZIP code nearest each city's Census center point. Frost dates: 50% (median) dates from the nearest NOAA station, 1991–2020 normals. Cities: the largest Louisiana places by 2024 Census population estimates, spread across the state, plus the largest place in each common zone. Large cities can span two half zones.
Which Parts of Louisiana Are in Each Zone?
Zone 8b, the coldest Louisiana zone, covers 27% of ZIP codes around Shreveport, Bossier City and Monroe. Zone 9b, the warmest with towns, covers 24% around New Orleans, Kenner and Houma. The table lists the largest places in every zone.
| Zone | Avg. coldest night | Share of ZIPs | Largest places in this zone |
|---|---|---|---|
| Zone 8b | 15 °F to 20 °F | 27% (190) | Shreveport, Bossier City, Monroe, Ruston |
| Zone 9a | 20 °F to 25 °F | 48% (344) | Baton Rouge, Lafayette, Lake Charles, Alexandria |
| Zone 9b | 25 °F to 30 °F | 24% (170) | New Orleans, Kenner, Houma, New Iberia |
| Zone 10a | 30 °F to 35 °F | <1% (6) | Rural ZIP codes only |
Places: incorporated places with 1,000+ residents, assigned the zone of the ZIP code nearest their Census center point.
What Do the Hardiness Zones Mean for Louisiana Gardeners?
A Louisiana gardener in zone 10a sees winter lows about 15 °F milder than one in zone 8b, so a shrub or perennial that thrives in one part of the state can die in another. Choose plants rated to your own ZIP code's zone or colder.
Hardiness zones follow latitude, elevation and large bodies of water rather than state lines. Higher ground and inland valleys that trap cold air usually sit in colder half zones, while cities, coasts and large lakes moderate winter lows. Within Louisiana, a plant labelled “zones 8–9” survives winter in at least 99% of ZIP codes, but plants at the edge of their range benefit from mulch and a sheltered spot. Enter a ZIP code in the USDA hardiness zone finder by ZIP code to check your exact half zone before buying perennials.
A zone describes winter cold only. Summer heat, humidity, rainfall and soil decide whether a cold-hardy plant thrives, and planting dates for vegetables follow frost dates, not zones: two Louisiana towns in the same zone can have last frosts weeks apart.
What Plants Grow Well Across Louisiana?
193 plants in PlantoScan's catalogue are hardy in every zone from 8b to 9b, the zones that cover 99% of Louisiana ZIP codes. Popular examples include hydrangea, chrysanthemum and poppy.
Hydrangea
Hydrangea macrophylla
Zone 5 – 9
AI generated
Chrysanthemum
Chrysanthemum morifolium
Zone 5a – 9b
PlantoscanAI generated
Poppy
Papaver somniferum
Zone 3a – 9b
AI generated
- DahliaDahlia pinnataPlantoScan
Dahlia
Dahlia pinnata
Zone 8a – 11b
Carnation
Dianthus caryophyllus
Zone 5a – 9b
AI generated
Azalea
Azalea indica
Zone 6a – 9b
AI generated
Arugula
Eruca sativa
Zone 5a – 10b
AI generated
Alfalfa
Medicago sativa
Zone 3a – 10a
AI generated
Calla Lily
Zantedeschia aethiopica
Zone 8a – 10b
AI generated
Hardiness ranges come from PlantoScan's plant database; gardeners in Louisiana's colder or warmer edge zones should check each plant's full range.
When Is the Last Frost in Louisiana?
Across most Louisiana ZIP codes, the average last spring frost falls between February 4 and March 16, from January 22 in New Orleans to March 11 in Ruston. Tender vegetables such as tomatoes go out 1 to 2 weeks after the local date.
The last and first frost dates for Louisiana cities include the safer 90% planting date, the fall frost date, growing season length and a tomato planting table for each city.
Frequently Asked Questions
- What planting zone is Louisiana?
- Louisiana spans USDA hardiness zones 8b to 10a on the 2023 USDA Plant Hardiness Zone Map. Zone 9a is the most common, covering 48% of the state's 710 ZIP codes, and zones 8b to 9b together cover 99%.
- What hardiness zone is New Orleans, Louisiana?
- New Orleans is in USDA hardiness zone 9b (ZIP 70128), where the average coldest winter night reaches 25 °F to 30 °F. Its average last spring frost is January 22 and its first fall frost January 5.
- What hardiness zone is Baton Rouge, Louisiana?
- Baton Rouge is in USDA hardiness zone 9a (ZIP 70806), where the average coldest winter night reaches 20 °F to 25 °F. Its average last spring frost is February 25 and its first fall frost November 26.
- What hardiness zone is Shreveport, Louisiana?
- Shreveport is in USDA hardiness zone 8b (ZIP 71109), where the average coldest winter night reaches 15 °F to 20 °F. Its average last spring frost is March 6 and its first fall frost November 19.
- What is the coldest hardiness zone in Louisiana?
- Zone 8b (15 °F to 20 °F) is the coldest zone in Louisiana, found in 190 ZIP codes around Shreveport and Bossier City. The warmest is zone 10a (30 °F to 35 °F).
Zones: 2023 USDA Plant Hardiness Zone Map ZIP code table, USDA Agricultural Research Service and the PRISM Climate Group, Oregon State University, used without changes. Frost dates: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals. City locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. PlantoScan is not affiliated with or endorsed by these agencies.