Anna E. Timmerman

Picking homegrown, tree-ripened citrus in your own backyard is incredibly rewarding. Citrus has been grown in Louisiana for over 300 years. Citrus fruits were brought to Plaquemines Parish by Father La Rue, a Jesuit missionary, who planted trees grown from seed 35 miles south of New Orleans. In the early 1800s, commercial groves were established along both sides of the lower Mississippi River in southeast Louisiana, all grown from seed as well. Today, citrus remains an important part of the state's horticultural landscape, supported by research and outreach from the LSU AgCenter.

Over the years, grafted and budded trees allowed for tasty cultivars of oranges, satsuma mandarins and lemons on hardy rootstock. A “satsuma boom” in the 1920s saw many groves planted along what is now the Interstate 12 corridor on the north shore of Lake Pontchartrain; however, severe frosts killed many trees, and most were not replanted.

Today, the majority of commercial citrus groves are in Plaquemines and St. Bernard parishes, with additional growers in coastal parishes further west. Frost and winter cold continue to be the primary limiting factor in home citrus production, limiting gardeners to hardy cultivars or container production in northern areas of Louisiana. Luckily, there are some great strategies that can be used, meaning that citrus can be successfully grown statewide. Through ongoing LSU AgCenter trials, new growing methods, such as container-grown trees, and management strategies that work on large- and small-scale groves are being developed.

Along the coastal areas and south of Lake Pontchartrain in Louisiana, all types of citrus can be grown, including the most cold-sensitive cultivars such as tangerines, limes and lemons. This is known as Zone I in the LSU AgCenter’s Louisiana Home Citrus Production guide, available as a free download on the website. In Zone II, which includes areas north of Zone I and Lake Pontchartrain up to around the Baton Rouge area, only hardy citrus can be grown in the ground, which includes calamondins, kumquats and satsumas. In-ground plantings of oranges, lemons, limes, grapefruit and other citrus may need to be covered or protected during freezes in this marginal zone. North of Baton Rouge to the state line is Zone III, which has regular hard freezes. In this zone, in-ground trees need to be covered for winter, and growers are limited to the most cold-hardy types of kumquats, calamondins and newly developed cold-hardy cultivars of satsumas, which can survive temperatures as low as 20 F once established.

Luckily, all varieties of citrus can be successfully grown in containers. This allows home gardeners to grow lots of tasty fruit by moving the trees indoors during cold weather. Citrus trees have been grown in containers for hundreds of years, most famously at Versailles in France since the 1400s. Potted citrus trees are stored in a glasshouse for the winter and wheeled back out to the garden for the warm seasons. Periodic root pruning helps maintain tree size and prevents circling roots.

The most cold-hardy citrus is the trifoliate orange, which can handle temperatures as low as -20 F. This tree produces seedy, inedible fruits, but is extremely tough against root rot pathogens and frost damage. This quality makes it a good rootstock for grafting and budding other types of citruses, imparting a few more degrees of cold tolerance to more sensitive fruits. A dwarf version of trifoliate orange, Flying Dragon, works in the same way but also imparts a smaller size at maturity for the cultivars grafted to it, creating dwarf trees that work well in containers and small yards. All citrus trees sold at garden centers are grafted or budded onto rootstocks, resulting in a tree that has a better chance of surviving and producing a crop.

Home gardeners can grow citrus in containers by planting them into 15-20-gallon pots. Use good quality commercially available potting soil or make a custom mix. Many container citrus growers recommend a 5-1-1 mix: five parts pine bark fines, one part potting soil or sifted compost and one part perlite. Choose pots that have adequate drainage holes in the bottom and no lip or indents that would make repotting difficult. Ceramic, plastic, terra-cotta, whiskey barrels or concrete planters all work well.

Citrus trees grown in containers are fertilized year-round, which contrasts with the schedule recommended for in-ground trees. Because nutrients leach out each time a container-grown tree is watered, all nutrients needed by the tree should be provided in the pot. There are excellent fertilizers specifically formulated for citrus trees available at garden centers. Follow the label directions for the size tree you have.

Container citrus trees should be moved indoors when there is a threat of frost. The roots are more exposed in a pot than they would be in the more insulated ground. Use a dolly to move trees indoors or into an area that will be maintained above freezing. Trees can go back outdoors when the danger of frost passes. In the most northern parts of the state, this strategy ensures that the trees live and thrive, leading to good fruit settings and production.

Citrus trees have a home here in Louisiana and can be grown and enjoyed statewide. Check your local garden center this spring and consider adding some to your landscape. The sweet rewards will be worth the effort.

Anna E. Timmerman is an AgCenter Extension agent for St. Bernard and Plaquemines parishes and is the state point of contact for citrus fruits.

This article appears in the spring 2025 edition of Louisiana Agriculture.

Grafting allows for an assortment of tasty cultivars. Photo by Anna Timmerman

A handheld refractometer can be used to test the brix level or amount of sugar in the fruit. Photo by Anna Timmerman.

Citrus in Zone III (blue) would freeze regularly. Zone II (green) is a marginal area where only the cold-hardy satsuma and kumquats should be grown. Zone I (yellow), the coastal area, is the primary area of commercial citrus production. Generally, all citrus types can be grown in this zone. LSU AgCenter file photo