In the fight about which side has the greener grass, two lawn care companies have taken aim at each other in a heated advertising war.

New commercials from the Scotts Co. and Pennington Seed Inc. take pot shots at their rivals' products. In one, Pennington describes Scotts' Turf Builder grass seed as "10 pounds of filler and 10 pounds of seeds."

Scotts responded in kind. Titled "Battleground," its ad features a Scottish man in front of a blackboard with an image of Pennington Smart Seed crossed out. Named "Scott," he then explains how the purported filler is actually a special coating that retains water. In a second ad, "Scott" refers to a Pennington product as "a bunch of ground up paper."

The lawn care war of words isn't a completely new phenomenon. The rivalry was bad enough in 2009 that Pennington filed suit against Scotts. Pennington argued that Scotts' ads had been misleading and harmful enough that it "[gained] an unfair advantage and to create the maximum amount of harm to Pennington," according to the Atlanta Business Chronicle.

Scotts then counter-sued Pennington for running misleading radio advertisements of its own. George Yuhas, general counsel to the Central Garden and Pet Co., which owns Pennington, told ABC News that the suit had no effect on advertising.

"The only thing that has changed is that we've gotten more aggressive in our to message to consumers," Yuhas said, adding that the suit has been settled out of court.

The Scotts Co. did not respond to requests for comment.

Clint Waltz, a turf-grass specialist at the University of Georgia, says that the heated rivalry is most likely the result of grass' being a perennial product and turf grass' being a lucrative industry. The turf-grass industry generates $2 billion annually in Georgia alone, Waltz said.

"When you put it into the ground it stays there," Waltz said. "You've got a single crack [to create] that brand loyalty."

Waltz, who has worked with both companies in the past on various studies, said even in the competitive turf-grass industry, the rhetoric used in recent ads has become increasingly heated in the past four to five years.

"I think they could behave themselves a little better," he said.