In order to make Chase Field the first baseball facility to combine enclosed air-conditioned comfort with the traditional playability of natural turf, it was necessary to develop a new strain of grass. The job fell to Steve Cockerham, one of the leading turf agronomists in the nation and head of the Department of Agricultural Operations at the University of California at Riverside.
After extensive testing, in which several varieties of grass were kept in shaded conditions for longer and longer periods of time, the winner was a zoysia blend know as DeAnza. While Chase Field was under construction in downtown Phoenix, the turf was planted at West Coast Turf in Palm Desert, Calif., under artificially shaded conditions designed to replicate conditions it would experience in Phoenix.
Early in February 1998, the turf was harvested, transported to the Valley of the Sun and installed. The playing surface rests on a bed of sand over gravel, into which drainage pipes have been installed. It would receive sunlight at every opportunity. Ellerbe Becket architects researched to what degree the roof must be opened on any given day to provide the turf with maximum light while giving the seating area maximum protection from the direct rays of the sun. When areas of the field receive too little natural sunlight, large growth lights provide a substitute.
The DeAnza experiment lasted for the entire 1998 season. Although much of the field did survive, the turf did not wear well causing several patches of brown to show for much of the second half of the season. After the season ended, all of the DeAnza grass was removed and the field was replanted for the 1999 season using Bermuda grass. The Bermuda turf was much more durable than the DeAnza and retained much of the green look. The new turf mixture became known as “BOBSod” and is sold to the general public through specialized nurseries.
The layout of the field includes a strip of turf between the warning track and the wall, giving outfielders double warning against a possible collision. Another visible feature of the field takes baseball fans at Chase Field back in time almost 100 years. There is a dirt path between the pitchers mound and home plate, reminiscent of the paths seen in very early pictures of the game. In a way, that path is symbolic of the Chase Field experience: The best of baseball history displayed in a setting that features all the modern conveniences.