The Texas A&M AgriLife Research program and turfgrass breeder Ambika Chandra, Ph.D., have officially released Cobalt hybrid St. Augustinegrass. After nearly 20 years of research and development, Cobalt was selected over other experimental turfgrass lines for its commercial potential.

“Cobalt will change how the industry views and uses St. Augustinegrass. Its drought resistance will reduce the frequency of irrigation needed to maintain a healthy lawn. Water is an extremely important resource and data shows that Cobalt is one of the most drought-resistant St. Augustinegrasses ever developed,” said Chandra.

Cobalt features drought resistance, shade and disease tolerance, has a good establishment rate and is winter hardy (USDA cold hardiness zone of 8a). Chandra said this selection has excellent visual quality with a dark green genetic color and a wide leaf blade and stolons.

St. Augustinegrass Research Group

The St. Augustinegrass Research Group (SARG) started in 2003 with a group of Texas sod producers to support and fund the breeding program at Texas A&M. The aim of this venture was to breed grass with good drought and disease resistance that grows fast and harvests well, producing good solid pieces of sod.

After many years of cross-pollination, work done in laboratories and field evaluations, a group of eight elite varieties was selected based on their performance at several test areas in Texas and across the Southeastern U.S.

These experimental lines were planted at two sod farms: Kubicek Farms in Wharton, Texas, and A-1 Turf Farm, Plano, Texas, in June and July 2018.

All eight lines were also evaluated for disease resistance, genetic color, overall quality and drought resistance. The grasses were harvested three times. All eight types of grass had their tensile strength evaluated with a device used by researchers. A group of producers was present during the harvesting to help identify the best grasses and make additional evaluations.

After years of observation, four advanced lines were selected based on their final evaluations for sod quality and performance at a sod farm.

Final four varieties

The final four varieties were expanded and planted in July 2020 in Wharton. Planting was done with a commercial plug planter and each plot covered a much larger area.

After one year of growth, the four selections were compared taking into consideration not only their performance in the larger plots but also considering data from research trials.

Cobalt was ranked as one of the top entries by the 2015 USDA-Specialty Crop Research Initiative warm-season grass research group for drought resistance where it was evaluated across five southern states (Texas, Florida, Georgia, North Carolina and Oklahoma). Likewise, Cobalt was evaluated across seven universities through the 2016 National Turfgrass Evaluation Program and was ranked in the top statistical group suggesting wide-range adaptation.

A second experimental grass — DALSA 1318 (a diploid) — will be evaluated for a couple more years because it has an excellent establishment ratio, growing faster than any other grass including Cobalt. It does not, however, have the same level of drought resistance or shade tolerance as Cobalt.

“With both 1318 and 1618, both have really good shade tolerance,” said Chandra. “With these, we now have a combination of shade tolerance and drought resistance. If you have a customer coming looking for a St. Augustinegrass for shade you have that with these varieties; and now you will be able to say these have significantly better drought resistance with reduced watering requirements too.”

“(Cobalt) consistently performs well at sites across the country from subtropical to transition zones,” said Sod Solutions president Tobey Wagner. “Studies showed it was cold tolerant and the 2021 polar vortex, when the air temperature dropped as low as 1 degree Fahrenheit, that blasted through the central and southern United States was the ultimate real-life test for this grass. Cobalt survived and thrived through the cold event.”

A 10-acre Foundation block of Cobalt was planted the first week of September 2021, using the plant material grown during the last 13 months. Now, Cobalt is being expanded across Texas and Florida. Wagner said that there is also a possibility of an international impact from Cobalt as the demand grows for drought-resistant, shade tolerant and disease resistant St. Augustinegrass grass.

Cobalt will be exclusively licensed through Sod Solutions for commercial production and marketing.