Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 70043 — Chalmette, LA

ZIP code 70043 (Chalmette, St. Bernard County) is in USDA zone 9b: the coldest winter night averages 25 to 30 °F. The median last spring frost is February 10 and the first fall frost December 17.

Where ZIP 70043 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone9b25 to 30 °F

Coldest night−3.9 to −1.1 °C

Last frostFeb 10

First frostDec 17

2012 zone9b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 9b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Chalmette, LA…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Chalmette, LA

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostFebruary 10median — 50% chance of a later frost

Safe for tender plantsMarch 8only 10% chance of frost after

First fall frostDecember 17median — 10% chance by Nov 21

Growing season309 daysfrost-free, median

A hard freeze (28 °F) usually ends around January 26 and returns around January 2.

From the NOAA station Chalmette, LA — within 1 mile, elevation 3 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 70043

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Dec 30 – Jan 13

SpinachSow outdoors · Dec 30 – Jan 20

Broccoli, cabbageStart indoors · Dec 2 – Dec 16

Broccoli, cabbageTransplant · Jan 20 – Feb 3

Onion setsPlant outdoors · Jan 13 – Jan 27

PotatoesPlant outdoors · Jan 20 – Feb 3

LettuceSow outdoors · Jan 13 – Jan 27

Carrots, beetsSow outdoors · Jan 20 – Feb 3

TomatoesStart indoors · Dec 16 – Dec 30

TomatoesTransplant · Feb 17 – Mar 3

Peppers, eggplantStart indoors · Dec 2 – Dec 16

Peppers, eggplantTransplant · Feb 24 – Mar 10

BeansSow outdoors · Feb 17 – Mar 3

Sweet cornSow outdoors · Feb 17 – Mar 3

Cucumbers, squashSow outdoors · Feb 17 – Mar 3

Fall lettuce, spinachSow outdoors · Oct 22 – Nov 5

GarlicPlant cloves · Dec 3 – Jan 7

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Feb 10) and first fall frost (Dec 17) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 70043 came on Jan 11 — 12 days earlier than the 1991–2020 average (Jan 23).

average
Jan 232026
Jan 11

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 9b in Louisiana

519 plants native to the lower 48 states, recorded in Louisiana, and rated by the USDA to survive 25 °F or colder — the bottom of zone 9b. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Chalmette, LA.

Soil in Chalmette, LA

The soil mapped at the center of ZIP 70043 is Cancienne — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables

pH5.7moderately acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter2.25%moderate

Hydrologic groupCwater soaks in slowly

Farmland classprime farmlandUSDA classification

Map unit: Cancienne silt loam, 0 to 1 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 70043; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Chalmette, LA

Summer high92 °Faverage high, July

Winter low44 °Faverage low, January

Hot days119days a year at 90 °F or more

Freezing nights6nights a year at 32 °F or less

Growing degree days7,457base 50 °F — the season’s usable heat

Longest day14 h 04 mindaylight on June 21

Shortest day10 h 13 mindaylight on December 21

Onions to growShort-daysummer days stay under about 14 h 20 min, so long-day varieties won’t bulb

Precipitation58.7 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Chalmette, LA (within 1 mile); precipitation: Chalmette, LA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 9b.

New Orleans, LA · 3 mi

701179b

New Orleans, LA · 4 mi

701149b

New Orleans, LA · 4 mi

701279b

New Orleans, LA · 5 mi

701269b

New Orleans, LA · 5 mi

All 2 ZIP codes in Chalmette → · Louisiana planting zones →

Questions about 70043

What planting zone is ZIP code 70043?

ZIP code 70043 (Chalmette, LA) is in USDA hardiness zone 9b on the 2023 map: the coldest night of an average winter reaches 25 to 30 °F (−3.9 to −1.1 °C).

When is the last frost in Chalmette, LA?

The median last spring frost (32 °F) near 70043 is February 10; after March 8 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Chalmette station.

When is the first frost in Chalmette, LA?

The median first fall frost near 70043 is December 17, giving a median frost-free growing season of 309 days.

When should I plant tomatoes in 70043?

Start tomato seeds indoors around Dec 16 – Dec 30 and set transplants outside around Feb 17 – Mar 3, one to three weeks after the median last frost.

How much rain and snow does 70043 get?

About 58.7 inches of precipitation a year (NOAA 1991–2020 normals, Chalmette station).

How hot do summers get in Chalmette, LA?

The average high peaks at 92 °F in July, with about 119 days a year at 90 °F or more.

What kind of soil does 70043 have?

The USDA soil survey maps Cancienne at the center of ZIP 70043: silt loam, somewhat poorly drained, pH about 5.7 (moderately acidic).

Did spring come early in Chalmette, LA in 2026?

Spring leaf-out near 70043 came on Jan 11 in 2026, 12 days earlier than the 1991–2020 average (Jan 23), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Chalmette, LA?

Short-day onions: the longest day near 70043 is 14 h 04 min, so summer days stay under about 14 h 20 min, so long-day varieties won’t bulb.