What Zone for Gardening Is Baton Rouge, Louisiana?

USDA Plant Hardiness Zone

• Based on the USDA plant hardiness zone map released in 2012, Baton Rouge falls in USDA zone 8b. Previously Baton Rouge fell in USDA zone 8. Experts believe the new map is more reliable than the old one because it took data from a 30-year period. The previous map used data from a 10-year period. The new map also reflects a warming trend.

Limitations

• Use the USDA plant hardiness zone map as a starting point when selecting perennials, shrubs and trees for your garden, but keep its limitations in mind. The USDA map is based on the average minimum temperature for Baton Rouge, which is 15 to 20 degrees. Its purpose is to help you determine which plants can survive winter. It doesn't consider things such as soil type, summer heat and humidity or the micro-climates in your garden.

Plant Selection

• The changes to the USDA plant hardiness zone map probably won't drastically change how you garden, but you might experiment with plants you avoided previously. Many gardeners can grow certain types of citrus fruit in Baton Rouge under the new guidelines. Fruit trees that require many hours of winter chilling to produce fruit might not perform as well here, advises the Louisiana State University Ag Center. Keep in mind that the map lists the average minimum temperature Baton Rouge receives. Actual winter temperatures can be much lower or higher. Grow tender plants, such as citrus trees, in a sunny, protected location and keep blankets or heaters on hand to protect them from cold weather.

Planting Times

• The USDA plant hardiness zone map doesn't offer information about first and last freeze dates -- an important consideration, especially for planting vegetable gardens. Although these dates can vary slightly from year to year, the average last frost date for Baton Rouge is around the first of March, while the first fall frost might not arrive until late November or December. This means that you can plant cool-season crops, such as lettuce, spinach and peas as early as February, but wait to plant tomatoes and other frost-sensitive crops until late March.