Scientists tour CityPark's pampered turf

Researchers visited the St. Louis soccer stadium to learn what makes the field's turf tick.


Josh McPherson speaking to a group of turf scientists on the field at St. Louis' CityPark stadium
Josh McPherson, director of stadium grounds for CityPark, the St. Louis SC’s home field, talks to a group of Crop Science Society of America visitors. Photo by Darrell J. Pehr

A crowd gathered in late October at the new, 22,500-seat CityPark Major League Soccer stadium in St. Louis. It was the morning before a really big game for St. Louis City SC – the first time the team had hosted a playoff game in club history. But this crowd wasn’t like the crowds of early birds often found camped overnight outside big venues, hoping to be among the first to get into a big-game venue or big-name rock concert, and this crowd wasn’t necessarily even aware of who would be playing later that day, although there were a few St. Louis City SC hats and jerseys among the crowd. These people were a lot more interested in the turf — the surface upon which the game would be played — rather than the game itself.

And like all gatherings of turfgrass scientists, it wasn’t long after the tour of the soccer complex began that faculty from across the world were eagerly crouching and kneeling in the grass, taking an up-close look at the pampered, deep green NorthBridge bermudagrass that carpeted the practice fields.

Josh McPherson, director of stadium grounds, hosted the first stop of the Oct. 29 turfgrass tour, part of the international annual conference of the Crop Science Society of America. The turfgrass scientists, students and others interested in turf make up a small percentage of the thousands of CSSA scientists attending the conference — plant science researchers whose expertise runs from forests to farmland.

McPherson gave us some big numbers to consider: The year-old practice fields and stadium, at the heart of downtown St. Louis, cost around $500 million. It’s a project of the Taylor family, who founded St. Louis-headquartered Enterprise Holdings (including Enterprise, National and Alamo car rental companies). “This is their love letter to St. Louis,” McPherson says. Below the stadium field’s bermudagrass-and-ryegrass-mix turf and 10 inches of sand are heating coils that rest on 4 inches of crushed rock. The field is fully heated with four zones, making play on green, healthy grass possible during harsh Midwest winters. Huge Gavita grow lights make sure even the shadiest areas of the field receive adequate lighting.

Around 40 events a year are held on the field, but no concerts, no football and no rugby.

“I’ll say yes to anything soccer,” McPherson says, which is in line with the ownership’s focus on all things soccer. “We really want to be known as the home of soccer,” a goal that is apparently resonating with the St. Louis community — more than 100,000 fans are on a wait list for season tickets.

The field — a flat pitch — can be vacuumed from below when it receives too much rainfall. The few weeds that manage to intrude upon this pristine, grass-only environment are quickly dispatched with a herbicide dauber. Some high-traffic areas like the goals and warm-up areas are further supported with stitched grass surfaces. Canopy shading in the stadium is the most extensive in Major League Soccer, helping keep the grass cool and happy even during the most intense Missouri summers. The playing surface sits about 40 feet below street level. It was built on a site owned by the Missouri Department of Transportation that included off-ramps constructed for Interstate 64 that had never been connected to the highway.

But the visit wasn’t a one-way street. McPherson, a 23-year veteran manager of soccer pitches, took the opportunity to ask the best minds in turfgrass science to consider some of his unique challenges. Namely, he asked whether research could be done on how to keep grass healthy while growing in a cozy heated root zone with much colder air above.

He’s also interested in the most effective growing light intensity and frequency for stadium conditions.

A chance to weigh in on ways to help make the premier soccer stadium’s turfgrass even better? Soccer fan or not, no doubt someone in the group will take up that challenge.

Darrell J. Pehr is GCM’s science editor.