In mid-December, Coronado city staff noticed a sudden and large growth under the lawn bowling green at the John D. Spreckels Center and Lawn Bowling Green. The growth, near the D Avenue side, was as high as six inches in some areas and was stretching the fabric of the greens. This caused about one-quarter of the greens to be cordoned off. It was unclear what the growth was or its source, but it was believed to be organic. The city began working with several universities to identify the growth, which is soft and springy with the texture and odor of a mushroom.
In January the city received the results of a sample taken from the growth. It turns out, according to Rutgers University, that it is a fungus, Pisolithus arrhizus, whose common names include Dyeball and Dead Man’s Foot, among others. The fungus may live on dead decaying material or in conjunction with living roots in the ground. It can produce enough pressure to lift asphalt. The city will begin working on a treatment plan, which may involve digging up the area to see the extent of growth. Although about one-quarter of the greens remain cordoned off and closed, the Lawn Bowling Green remains open for play.