Gretna, LA 70158 Frost Dates
70158, near Gretna, LA: the frost window
Typically, the last spring freeze lands around 02/01, roughly 157 days out. Fall's first freeze usually shows up around 12/31, roughly 330 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Gretna in Zone 9b (25 to 30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Gretna's growing season runs out in roughly 18 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 02/01 isn't a guarantee
02/01 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/06 and only about 1 year in 10 sees frost after that.
Gretna against the rest of the dataset
Gretna's growing season runs about 330 days, ranking 3,012 of 40,283 US ZIP codes measured here, longest to shortest. Within LA, it ranks 51 of 710.
Learn more
Two guides worth reading on 70158: zone vs. frost date, on why Zone 9b and Gretna's frost date answer different questions, and the frost range, on how to read the range around Gretna's dates instead of trusting one.