Blueberries, like many cultivated fruits, come in numerous varieties or cultivars. These differ with respect to where they grow and fruit well. An ongoing LSU AgCenter demonstration orchard at the Hammond Research Station is helping educate Louisiana growers about how different blueberry varieties perform and how they can successfully grow blueberries.

One of the factors that determines what varieties are productive in a given location is the chilling requirement needed to break dormancy. Varieties that require too many chilling hours for a location will not fruit well on a regular basis, while ones that require too few are likely to flower too early and have flowers or young fruit killed by a late freeze.

The blueberries that have typically been planted in gardens in the Deep South are rabbiteye blueberries (Vaccinium ashei or V. virgatum). These plants are forgiving of less-than-ideal soil conditions and can live for many years. Common varieties include Premier, Tifblue, Climax, Brightwell and Powderblue. These five have been around for many years. A number of newer varieties released in the past 35 years have expanded the range of options, but some of these have not been widely evaluated in Louisiana.

Besides new rabbiteye cultivars, there are also Southern highbush blueberry varieties. These are crosses between the northern highbush blueberry (V. corymbosum) and other native blueberry species, such as V. darrowii. These generally fruit earlier than rabbiteye varieties and dominate the commercial blueberry industries in states like Georgia, Florida and North Carolina. However, they are more finicky about soil conditions than rabbiteye blueberries. Having an appropriate soil pH and good drainage are critical when growing these. They also tend to be more susceptible to plant diseases.

A Hammond Research Station demonstration established in the fall of 2020 has provided opportunities to observe the performance of five “old standard” blueberry varieties alongside 12 newer rabbiteye and related varieties and 13 Southern highbush blueberry varieties. While the main purpose of this planting at the Hammond Research Station is to demonstrate the performance of different blueberry varieties in our climate, one of its major uses has been to teach people how to prepare the soil for planting blueberries.

Plant survival has been excellent. Of 93 plants (three of each of 31 varieties), one plant of the rabbiteye variety Centurion has died. The 2023 season, when the site experienced 26 F on March 20, was an especially useful one for learning what varieties are more likely to produce in years with late freezes. Of the old standards, Brightwell was a clear winner in terms of producing despite the freeze. Among other rabbiteye varieties that typically ripen in the early to middle part of the season, Austin, Columbus, Alapaha and Tifblue also fared relatively well. Among ones that tend to ripen later, Centurion, DeSoto and Ochlockonee had respectable amounts of fruit. The only Southern highbush variety that stood out for producing despite the late freeze was Gupton.

In 2024, Louisiana Master Gardener volunteers helped harvest fruit to collect yield data. It is important to note that this is a demonstration rather than a research study. To be legitimate research, varieties would need to be replicated randomly within the area so that we could be confident that differences were due to the varieties themselves and not to soil conditions in the spot where a variety was planted or other variables. Nevertheless, collecting yield data from this demonstration does provide some useful information. Tifblue and Ochlockonee were the top-yielding rabbiteye cultivars, while Legacy and Pearl were the highest yielding Southern highbush cultivars. For more detailed yield information, see results below.

Varieties varied a great deal with respect to when fruit ripened. Most Southern highbush varieties — Camellia, Colibri, Emerald, Farthing, Gupton, Keecrisp, Miss Lilly, Paloma, Patrecia, Pearl, Suziblue and Star — had ripe fruit by the end of April or beginning of May. Legacy, the highest yielding variety, did not start producing in mid-May, comparable to some of the earliest rabbiteyes. Only dates when an average of at least 10 grams per plant was harvested from a variety were counted.

Robeson and Pink Lemonade, which have both Southern highbush and rabbiteye genetics in their backgrounds, started fruiting in the second week of May, and the rabbiteye varieties Austin, Brightwell, Krewer and Vernon started producing in mid-May. Of these, Austin and Brightwell fruited through the last harvest on July 8.

Harvest of a number of rabbiteye varieties — Alapaha, Climax, Delite, DeSoto, Powderblue, Premier and Titan — began on May 20. Columbus started a few days later. All of these except Titan continued fruiting till near the end of June or first of July. Ochlockonee and Tifblue started fruiting in late May and were still producing at the last harvest in early July. Onslow and Centurion began June 6, which was the latest, and produced through the last harvest.

Yields of the earliest ripening varieties were generally unimpressive, but this was not solely the fault of the varieties. When there were fewer berries, as there were at the beginning and end of the season, birds likely consumed a larger proportion of them. A few of the earliest varieties also had small amounts of fruit before yields were documented. A second year of harvesting is planned to have two years of yield data.

Attempting to grow fruit plants, commercially or at home, can result in abundant harvests and great satisfaction or in wasted money and disappointment. The LSU AgCenter provides information to help people make decisions that will increase their chances of success.

Mary Helen Ferguson, an AgCenter Extension agent focusing on horticulture, is based in Tangipahoa Parish.

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

Site Preparation for Blueberry Demonstration at the AgCenter Hammond Research Station

Rabbiteye blueberries can produce for many years and with relatively little care if a good site and appropriate varieties are chosen and the soil is prepared well. Full sun exposure, good drainage and a soil pH around pH 4.5 to 5.2 are desirable, although rabbiteye varieties can tolerate slightly higher pHs (up to about pH 5.5).

To prepare the demonstration at the LSU AgCenter Hammond Research Station site for planting, aged pine bark was spread to a depth of 2 to 4 inches in a 3-feet-wide strip on rows where rabbiteye varieties would be planted. Where Southern highbush plants would be, the mulch depth was increased to 4 to 6 inches. Mulch was rototilled into the soil, and the soil-bark mixture was hipped into raised rows with discs pulled by a tractor.

After planting blueberries (6 feet apart for rabbiteye plants and 4 feet apart for Southern highbush plants), additional pine bark was spread on the tops of rows for weed management. Blueberry plants have shallow root systems, and it is important to keep turfgrass and other weeds away from the bases of the plants, especially while they are getting established.

Drip irrigation tubing was installed after planting and before applying the surface mulch layer. This is an option for home gardens as well, but is not absolutely necessary. In a small planting, watering can be done by hand while plants are getting established and during dry periods.

The period between late fall and early spring is a good time for planting containerized blueberry plants, as this allows them to grow roots before summer heat arrives. Bare root plants should be planted while dormant. Plant at least two varieties for cross pollination.

Southern highbush varieties tend to be more finicky about soil conditions, and the early-fruiting ones are likely to have flowers killed by late freezes in many years. One option is to plant these in 10- to 15-gallon pots with aged pine bark as the substrate. This will require more attention to watering and fertility than if they were planted in the ground, but it allows a person to move them into a protected area during late freezes.

Rabbiteye blueberries grow at a blueberry variety evaluation at the LSU AgCenter Hammond Research Station. Photo by Olivia McClure

Southern highbush blueberries planted at the AgCenter Hammond Research Station are being monitored in a long-term evaluation. Photo by Mary Helen Ferguson

Hammond Research Station Blueberry Demonstration Results

Values are yield per plant averaged over all plants of that variety.

Rabbiteye Blueberry Cultivars

– Top 10 Producers in 2024 –

Tifblue 19.2 lbs.

Ochlockonee 18.3 lbs.

Brightwell 17.5 lbs.

Premier 12.2 lbs.

Austin 12.1 lbs.

Alapaha 9.6 lbs.

Powderblue 9.1 lbs.

Centurion 8.5 lbs.

DeSoto 6.8 lbs.

Vernon 6.8 lbs.

Southern Highbush Cultivars

– Top 5 Producers in 2024 –

Legacy 8.4 lbs.

Pearl 6.2 lbs.

Gupton 6.1 lbs.

Farthing 4.6 lbs.

Suziblue 3.8 lbs.