(01/14/22) LAFAYETTE, La. — LSU AgCenter extension agents and researchers are reaching out to commercial landscapers and landscape architects with a burgeoning series of landscape management classes designed to introduce stakeholders to the latest recommendations and services.

One of the first of these gatherings was hosted at the University of Louisiana at Lafayette’s Ira Nelson Horticulture Center on Jan. 11. The comprehensive event was organized by horticulture extension agents Dan Devenport, of Lafayette Parish, and Stuart Gauthier, of St. Martin Parish. They highlighted the services that the AgCenter provides, such as soil and water testing, plant nutrient testing, insect identification and disease identification through the LSU AgCenter Plant Diagnostic Center.

The two dozen landscapers in attendance heard from several AgCenter researchers and industry professionals who discussed a range of topics including water runoff management, new cultivars, plant disease identification and herbicide applications.

Damon Abdi, LSU AgCenter assistant professor of landscape horticulture, described his detailed work with trying to find more efficient and environmentally friendly irrigation methods for container plant nurseries. Abdi described his work observing water runoff using three methods of irrigation: overhead sprinkler systems, overhead sprinkler systems with substrate moisture sensors and drip irrigation via spray stakes (also with sensors).

Abdi said the data collected showed the overhead sprinkler systems to be the least efficient irrigation method, while using sensors to measure moisture greatly reduced runoff, nutrient loss and even fertilizer use.

“We cut the water use down by about 50% just by using sensors to make more informed decisions about how much irrigation to put down,” Abdi said. “The spray stakes cut down about 80%.”

Abdi said the use of spray stakes also abated the problem of surface runoff in the 16 raised beds tested in his trial at Michigan State University.

Adding a splash of color to the gathering was Allen Owings, of landscape plant wholesaler Bracy’s Nursery. Owings, a former AgCenter horticulturist, presented the group of landscapers with a bevy of new cultivars that are emerging throughout the southeastern U.S. Of the many trends that he described, one of the more prominent changes has come as a shift in preference of rose species among landscapers.

“We are matriculating away from Knock Out roses and going more toward drift roses,” Owings said. “Some of the new colors of drift roses that have come out are peach, apricot, white and popcorn.”

As Louisiana enters its coldest annual weather pattern, Owings said, it is approaching the time for winter pruning roses. Late January to early February is the ideal time for a major pruning of knockout or drift roses, with a minor pruning best fit for late August or early September.

Jeb Fields, AgCenter assistant professor and extension specialist, focused on his work with sustainable landscape horticulture. Fields said it is important for landscapers to keep in mind the four tenets of sustainability when planning a project or method of work: resource conservation, socially supportive, commercially competitive and environmentally sound.

“That is what sustainability is,” Fields said. “These are practices that maintain existence with little impact with less management needed.”

Owings stressed that to create a sustainable landscape project, it must be aesthetically pleasing.

“If you like the way it looks and it’s your landscape, you’re going to keep it that way,” Owings said. “If you don’t like it, I don’t care how beneficial it is, you’re not going to keep it that way.”

Raj Singh, an associate professor who oversees the Plant Diagnostic Center, discussed common plant diseases that are plaguing plant lovers across the region. Singh said Louisiana’s warm, wet climate makes the Bayou State a prime breeding ground for diseases, such as armillaria root rot and boxwood dieback. He said keeping plants free of unnecessary stressors is one way to aid in managing these horticultural maladies.

“The weakest link is dispersal,” Singh said of these parasitic diseases. “If you are able to stop dispersal of the spores, you can get it to the level where they are not causing aesthetic damage.”

Singh added that accurate, early detection is key when identifying these diseases. For those who are not sure what diseases are plaguing their shrubs, trees or flowering shrubs, Singh and other researchers are capable of testing plant tissue to identify plant ailments at the Plant Diagnostic Center.

Ron Strahan, LSU AgCenter turfgrass specialist, outlined new herbicides that have recently hit the market. He said Bayer has released Celsius Xtra which replaces dicamba with halosulfuron for stronger sedge control. The PBI/Gordon Corporation has released Vexis, a granular herbicide that targets sedges and is labeled for certain broadleaf weed species. But Strahan said he likes a particular product that offers pre-emergence control of both sedges and broadleaf species.

“CoastaI — I really like this one a lot,” Strahan said of the Sipcam Agro product. “You get early-post activity from the Simazine. Imazaquin for general sedge activity. And it has Prodiamine, a very good pre-emergence herbicide.”

In preparation for similar events in the future, participants were asked to provide a list of landscaping discussion topics they would like to see addressed by researchers and extension.

“We want to start a dialogue about some of the issues you are facing,” Abdi told the commercial landscape professionals. “We can then use that to influence the direction of our respective programs. I really look forward to being able to continue to work directly with the industry members to build a program that is really going to reflect the needs and challenges that you are facing.”

LSU AgCenter turfgrass specialist Ron Strahan describes some of the latest offerings on the herbicide market at a commercial landscape management class hosted by the LSU AgCenter at UL Lafayette’s Ira Nelson Horticulture Center on Jan. 11

Raj Singh, better known as the LSU AgCenter plant doctor, explains effective management strategies of landscape plant diseases at a landscape management class held in Lafayette on Jan. 11. In attendance were commercial landscapers from the Acadiana area.