This is the second story in Sportico’s Turf Wars series, examining the business decisions behind choosing natural grass or artificial turf for an NFL stadium.

Denver Broncos executives were watching the team’s home game against the Arizona Cardinals on Dec. 18, 2022, when they realized they had a problem: The grass at their stadium was no longer up to snuff.

“It was a combination of players slipping, or the chunks of grass that come up when a player cuts,” team president Damani Leech said in a recent interview. “The surface just didn’t appear to be holding up in a way that we felt comfortable with.”

The team took a radical step. After brief conversations between coaches, executives and the franchise’s new owners, the Broncos replaced the entire surface, at a cost of roughly $400,000, for the final game of the season. Sod was trucked in from Arizona and laid in Empower Field at Mile High just a few days before the last-place team ended its season against the Chargers. It was used for one NFL game, then replaced again before the 2023 season started.

The move stands out as a notable chapter in a growing issue across the world’s richest sports league. The debate over natural grass vs. artificial turf has simmered for decades, but it’s become more contentious in recent years as franchise valuations soar and players become more vocal about their preference for grass.

This season, 17 teams will play home games on artificial turf, and 15 will play on natural grass, including the Green Bay Packers, who play on a hybrid field—though it’s hard to imagine NFL Films hyping up the “frozen synthetic and grass tundra of Lambeau Field” any time soon.  

As the NFL and union collaborate to create a league-wide standard for surfaces, a process outlined in the first story in this Sportico series, the two sides continue to disagree on whether artificial turf leads to more injuries. Last year, NFLPA executive director Lloyd Howell called for all teams to switch to natural grass. The debate is driving strategic investments and influencing stadium design. It even popped up at the Super Bowl, the league’s most important game.

For now, teams are largely free to use whatever surface they’d like. The Broncos—whose ownership group, led by Walmart’s Walton family, is the richest in the NFL—believe grass is best for them. And sometimes that might require a late-season scramble, which we saw at the end of 2022.

“It definitely set the tone across the organization about what this ownership group is about: focused on winning and willing to spend the money,” Leech said. “You’re not just saying it, you’re putting players in an environment that helps with their health and safety.”

In the last few months, Sportico spoke with about a dozen NFL league and team executives to get a better idea of why they chose the specific surface in their venues. Those conversations highlighted how many different variables go into the decision, including local climate, sun angles and stadium infrastructure. Good grass, almost everyone agreed, is better than mediocre artificial turf, while good turf is better than bad grass.

Like almost everything in the NFL, money is also a big component. Owners differ in their financial tolerance, their building’s calendar during the NFL offseason, and their obligations regarding public-private partnerships that allow them to collect hundreds of millions in taxpayer dollars.

“[Leaguewide] facilities are not cookie-cutter, so it’s very challenging to provide a one-size-fits-all solution on the surface,” Nick Pappas, the NFL’s field director, said in an interview. “You’re talking about indoor vs. outdoor or a retractable roof, you’re talking warm season vs. cool season, you’re talking transition zones, you’re talking nearly single-use facilities vs. multi-use facilities, that may be [hosting] college football or MLS, soccer, concerts or Monster Jam.”

For players, health and safety has become the critical lens for this debate. NFLPA members almost uniformly prefer grass to artificial turf. It’s much easier on the body on a day-to-day basis, and owners have accepted that in at least one realm—every NFL team has grass for their outdoor practice fields, regardless of what surface they use on gamedays.

But just like owners, there are economic considerations as well. Players receive nearly 50% of NFL revenue, per terms of the CBA. That share doesn’t include direct revenue from concerts or non-NFL events in venues owned or controlled by NFL teams, though other events in those venues help command higher sponsorship and suite sales, revenue that does get shared with players.

“While we know there is an investment to [getting rid of artificial turf], there is a bigger cost to everyone in our business if we keep losing our best players to unnecessary injuries,” Howell, the union boss, said last year after Jets quarterback Aaron Rodgers tore his Achilles tendon on the artificial turf at MetLife Stadium. “This is worth the investment, and it simply needs to change now.”

The costs to install and maintain grass vs. artificial turf, on their face, aren’t materially different. Numbers across the league vary, but most teams that Sportico spoke with said a new grass sod field costs in the $300,000-$500,000 range. That might need to be replaced once or twice per year for most teams, or up to 10 times per year in rare cases (like the Dolphins), depending on the venue’s usage. There are also added infrastructure costs, such as field maintenance, grow lights, hydronic heating, aeration systems, staff and fertilizer that can add $1 million annually. With costs averaged out, a franchise could spend a few million per year on a grass field.

Artificial turf, on the other hand, costs more to install but lasts longer. A turf field typically costs $1 million to $2 million and lasts in the three-to-five-year range (in some high-use buildings, such as Atlanta’s Mercedes-Benz Stadium, it’s every two years). There are still maintenance costs of course—a loose screw that falls from a concert set, for example, must be located and removed before an NFL team takes the field. And individual pieces of the artificial turf can get worn and need replacing.

In July, the Indianapolis Colts’ Lucas Oil Stadium installed Hellas’ Matrix Turf for $1.65 million—the same surface as SoFi Stadium, AT&T Stadium and NRG Stadium. Previously, Indianapolis had slit film turf, which has openings in the pieces, which potentially creates a higher risk of cleats catching in the material versus a single blade system (monofilament). The union argues the rate of non-contact and lower extremity injuries are statistically higher on slit film artificial turf fields.

Minnesota, Detroit and New York have also recently scrapped slit film, the field surface that former NFLPA president JC Tretter has called for a ban; there are no 100% slit film fields left, although Carolina and Buffalo have multi-fiber fields of slit film and mono.

The opportunity cost of grass versus artificial turf, however, is quite different. Grass deteriorates at a much faster rate if there are other events on the surface, be they other sports or concerts. Both surfaces are typically covered with plastic paneling for many non-sports events, but grass is more fragile and has light requirements that turf does not. This is perhaps the biggest variable in an NFL team’s approach.

One of the main reasons behind the Broncos needing to replace that field at the end of the 2022 season, Leech said, was due to a local high school football game played on the surface during inclement weather earlier in December, which resulted in the field being more torn up than usual. Last season there was just one non-NFL event played at Mile High during the season, an Air Force game contracted years prior, and the team has cleared the entire calendar for this season. The Foo Fighters played Empower Field on a Saturday in early August this year, and that will be the last non-Broncos event in the field until after the 2024 season ends.

As such, the Broncos plan to utilize two grass fields this season, with a re-sod coming in the middle of the year. That’s true for the Browns, as well. The team’s lakefront stadium hosted a WWE event in early August, then installed its first of two planned natural sod fields for the season. They’ll cover the grass when Billy Joel and Rod Stewart play the stadium in September, one of the few non-NFL events in the venue during the season, then plan to put in another grass field for the rest of the NFL season.

Contrast that with the Carolina Panthers. The team was playing on grass when billionaire David Tepper bought the franchise and its stadium for $2.28 billion in 2018. The NFL’s richest owner until the new Broncos owners took over, Tepper bought an MLS expansion team that began play in Bank of America Stadium in 2022. During the typical NFL season, the venue currently has more than a dozen non-Panthers events, including MLS games, college and high school football, and concerts.

In 2021, shortly before the soccer team’s MLS debut, Tepper announced that the stadium was switching to artificial turf, citing the volume of events at the venue. The team said it would be difficult to maintain playing fields for both franchises, particularly in the NFL bench areas where it is hard to grow grass; that area is in the MLS field of play. The switch quickly drew ire of players on the Panthers, and those on visiting teams.

The anger grew after Tepper, one of just five NFL owners who actually owns the team’s stadium as well, installed a temporary grass field in July 2022 for a soccer exhibition between Charlotte FC and English soccer giant Chelsea. Linebacker Shaq Thompson, who is still on the team, suggested that year that players stop going to practice until the grass returned. The team continues to play on turf, though grass was installed again this year for a Real Madrid-Chelsea exhibition. The Panthers declined to comment for this story.

NFL owners often swap artificial turf for grass when European soccer teams come to play in the U.S. When the 2026 men’s World Cup comes to North America, all 11 NFL venues hosting games will feature grass, which is a FIFA requirement. Soccer players, however, are much smaller than NFL players and therefore have much different requirements for grass. When the NFL plays in Tottenham Hotspurs’ $1.5 billion stadium in London, for example, they play on the venue’s artificial turf, not its grass.

Carolina is one of five NFL franchises that currently shares a field with an MLS team, and Chicago’s Soldier Field is the only grass venue that hosts NFL and MLS games. Tretter called out the field in Chicago ahead of a 2022 preseason game—“The NFL can and should do better,” he said. The stadium’s Kentucky bluegrass was replaced with the current Bermuda blend before the 2022 regular season, and field complaints largely dissipated.

Grumbling about the Soldier Field playing surface popped up again last month during a preseason game against the Cincinnati Bengals, with kicker Cairo Santos calling out “some loose pieces.” Soldier Field had recently hosted two Metallica concerts, and as a result, the field was re-sodded later than usual, according to coach Matt Eberflus.

Increased events present a major challenge to maintaining grass fields. Soldier Field only has one non-NFL or MLS event on its public calendar for the rest of the year. The Packers last hosted a concert inside Lambeau Field in 2019 for Paul McCartney. The Browns hosted only two concerts since 2018 before the Rolling Stones played in June.

In contrast, Mercedes-Benz Stadium, home to the Falcons and MLS club Atlanta United, is one of the busiest arenas in the world and occupied almost every day of the year—the main kitchen at the stadium was used all but 14 days in 2023. The building, whose playing surface is FieldTurf, hosted 3 million people last year at pro sporting events, concerts, college and high school football games and 115 private outings.

The $1.5 billion venue opened in 2017 as a public-private partnership, with the city contributing $200 million of the cost and the Falcons responsible for the balance, including $200 million from the NFL’s stadium fund. The city’s approval of the project and financial contribution was contingent on the stadium hosting more than a dozen “legacy” events previously played at the Georgia Dome that generated an economic benefit for the city.

The MLS season will be completed by December, but over five weeks starting Dec. 1, Mercedes-Benz will host three Falcons games, the SEC championship, the Peach Bowl, Cricket Celebration Bowl, three days of high school football games, and 4,000 Delta employees on the field for a Christmas party. That doesn’t work on grass.

SoFi Stadium and MetLife Stadium are in similar situations; both stadiums host a pair of NFL teams, in addition to a full slate of concerts, high school and college football, and private events. AT&T Stadium has more than 25 major ticketed events annually that draw at least 50,000 fans outside of Dallas Cowboys games. The three stadiums all generated more than $50 million in profit last year from non-NFL events for the Cowboys, Rams and Giants and Jets, who split the event haul at MetLife.

The Buffalo Bills’ $1.7 billion stadium is scheduled to open in 2026 and will almost certainly be the last NFL venue built for less than $2 billion. The next round of new buildings will need to host more than NFL games to justify the cost and help owners pay down construction debt. Cities want more than just football at these venues if they are going to foot part of the cost. Six of the last eight stadiums built installed artificial turf surfaces, including SoFi, Mercedes-Benz, MetLife and AT&T.

Teams generated more than $500 million in profit last year from non-NFL events, according to Sportico estimates as part of its NFL team valuations. The total was boosted by Taylor Swift, whose 53 U.S. shows all took place at NFL stadiums. Swift kept almost all ticket revenue, with teams entitled to a small cut or rental fee for their venue. Yet, teams cashed in with concessions, parking and merchandise at the sold-out events, netting $4 million or more per night after expenses for Swift’s concerts. Swift won’t be touring every summer, but live events in general have rebounded since COVID-19 shut them down.

The Miami Dolphins took a unique approach to their field’s quality-control efforts when owner Stephen Ross bought 80 acres of land in Palm Beach County for a reported $3.6 million in 2018 and developed a sod farm. The previous Hard Rock Stadium fields looked good on TV, but the surface quality was subpar, and players struggled with slippery conditions in late 2017.

South Florida Sod Farm is located just an hour from Hard Rock and allows the club to better control quality and change the field on short notice, which it does eight to 10 times a year on average. The proximity also cut shipping costs by nearly $1 million versus the previous two field sources.

“As the Hard Rock Stadium calendar of events expanded in the last decade, our need for access to high-quality grass did as well,” said Dolphins executive Brandon Shore, who oversees the sod farm. “From the very beginning, our primary goal was to be in control the quality of our grass from the time the seed is laid, the grass is grown, transported and eventually installed to be ready for play.”

While it’s unclear if other teams are looking to mirror that approach, it is clear that NFL franchises will likely differ in their surfaces for a while. The league and NFLPA are working together to create more uniformity, but those conversations have centered around preserving the top-level choice: Teams can keep their grass, or turf, or hybrid.

“It’s the club and the venue’s goal to provide a surface that performs the best for them, throughout the entire season, start to finish, based on business model and climate,” Pappas, the NFL’s field director, said. “Sometimes that’s going to be an artificial field, and sometimes that’s going to be a grass field.”

(This story has been updated in the ‘Serving Soccer’ section in the 24th paragraph with news that the Carolina Panthers declined to comment.)