Gardening in Louisiana

Hardiness zones in Louisiana

Louisiana spans USDA hardiness zones 8b through 10a. The zone number reflects the average annual minimum winter temperature recorded at weather stations across the state. It says nothing about summer heat, rainfall, or the soil in your yard. Data pulled from 94 weather stations across Louisiana show four zones present in the state: 8b, 9a, 9b, and 10a. The coldest zone recorded is 8b, and the warmest is 10a. Use your zone to judge which plants can survive winter outdoors where you live. A zone number alone will not tell you when to plant or how much water a plant needs. Check the specific zone for your location before you choose a shrub, tree, or perennial meant to stay in the ground through winter.

• Zone 8b
• Zone 9a
• Zone 9b
• Zone 10a

Frost dates

Frost timing varies across Louisiana's 94 weather stations. The last spring frost date with a 50 percent chance of occurring ranges from January 22 at the earliest station to March 30 at the latest. The first fall frost date at that same probability ranges from January 1 to December 31 across the stations. This wide spread shows how much frost timing differs by location within the state, rather than one single date you can apply everywhere. The growing season, the number of frost-free days between those two dates, ranges from 221 days at the shortest station to 357 days at the longest. A gap of well over 100 days separates the shortest and longest growing seasons recorded. Check the frost dates for the station closest to you rather than relying on a single statewide figure. Plan frost-sensitive planting and harvest dates around your local last and first frost dates, not a calendar month.

Climate

Louisiana's climate data, drawn from 94 weather stations, points to a state with a long warm season and mild winters. Hardiness zones across the state run from 8b to 10a, which reflects average annual minimum winter temperatures, not summer heat or rainfall totals. The growing season length backs up this picture: frost-free stretches run from 221 days at the shortest recorded station to 357 days at the longest. A station with 357 frost-free days sees almost no true winter at all, while one at 221 days still goes several months without frost. Last frost dates in spring range from January 22 to March 30 depending on the station, and first frost dates in fall range from January 1 to December 31. That spread means two gardens in the same state can face very different planting calendars. Treat any statewide number as a range to narrow down with your own local station data, not a single figure to plan a whole season around.

Season length

Growing season length is not the same everywhere in Louisiana. Across the state's 94 weather stations, the frost-free season runs from a low of 221 days to a high of 357 days. A 357-day season leaves almost no stretch of true winter, while a 221-day season still leaves several months without frost. This range comes from the same spread seen in the state's frost dates, where the last spring frost and first fall frost both vary by station. Look up the season length for your closest station rather than assuming the statewide average applies to your yard. Use that local figure to plan how long you can keep frost-sensitive crops in the ground.