Shoal Creek Vitex (Photo by Dan Gill)

LSU AgCenter research associate Joey Quebedeaux, center, shows olive tree varieties that will be planted at the AgCenter Hammond Research Station as part of the Plants with Potential research project. (Photo by Johnny Morgan)

BATON ROUGE, La. – Many varieties of shrubs and trees are no longer grown in Louisiana landscapes, but that’s about to change with the help of LSU AgCenter researchers.

Jason Stagg, an instructor at the LSU AgCenter Hammond Research Station, and AgCenter horticulturist Charles Johnson have begun a project called Plants with Potential. They are taking seeds and making crosses to develop varieties of ornamental plants that complement and at times substitute for existing plants, such as crape myrtle.

Johnson started on the project two years ago after working on improving peach varieties in Louisiana for more than 30 years.

“Some of the plants lend themselves well to be used as foundation plants and as shrubs,” Johnson said. “One plant we decided that we needed some new varieties of is vitex, and I started making some crosses with the known varieties that we had.”

The researchers are making selections now for different bloom colors, different architecture and different forms, such as bush or shrub-type plants.

Vitex produces lots of seed, which concerned Johnson because he doesn’t want it to become an invasive species.

“We can start collecting seeds from these plants around July, but they are not viable for very long,” Johnson said. “By September the viability of the seed is pretty much gone.”

The project is now in the second cycle and making steady progress, Johnson said.

“We started with about 600 seedling from those first crosses, and we selected from those about 20 plants that we thought were superior,” he said.

The point of the project is to evaluate plants that are not well known in Louisiana but will do well in this climate.

“As we travel around and discover new plants, we’ll collect them because they are not patented,” Stagg said. “We’ll bring them back and start propagating them.”

The benefits of the project is to increase the diversity of plants for Louisiana growers and the retail and wholesale industry.

Other plants in the project are being grown at the station for distribution to area growers for trials, Stagg said.

These plants include Kapioloni Bronze copper plant, Masaica copper plant, Barbara Rogers begonia, Aureoreticulata iresine, Belle Starr Gold lantana, Mary Helen geranium, Nova pentas, Florida dwarf rose purslane, Silke’s Dream salvia and trailing yellow turnera.

Olive trees are another plant that the AgCenter is getting more questions about, Stagg said.

Over the years, different groups, such as herb societies and local plant sales, have been offering olive trees, and some are varieties from Spain, Italy or Tunisia, he said.

“With the growing number of questions we were getting, the station was awarded a grant to install an olive orchard and trial a number of different varieties,” Stagg said. “We need to provide reliable data to the consumer and to the industry on which olive tree varieties will do well in Louisiana because some are not very cold-hardy.”

Another question to be answered is how olive trees will tolerate Louisiana’s high amounts of rainfall because the Mediterranean area doesn’t get as much rainfall.

“We are looking at 15 different varieties of edible olives to see how well they do in our hot, humid climate,” Stagg said.

The plants in the project will be rated for at least two years to get good data to answer some of the questions about olives and the ability of the other plants to survive in the Louisiana landscape.

Johnny Morgan