A misapplication of herbicide turned Colorado golf course's fairways from green to brown

• City Park Nine Golf Course fairways turned brown due to misapplication of the herbicide Semera.
• The extent of the damage and cost of reseeding is currently unknown.

Lush green fairways that turned brown in recent days at the city-owned City Park Nine Golf Course aren't from a lack of water, but due to a misapplication of an herbicide.

Scott Phelps, the city's Golf Division manager, said the herbicide Semera was mistakenly used in a mixture containing fertilizer and wetting agent on the course's nine fairways June 25. Phelps said by June 28, the fairway grass discoloration became more evident and he was notified June 29 of the misapplication.

"We were looking fantastic up until then," Phelps said. "Unfortunately, somehow it was grabbed off the shelf ... They saw that it killed weeds but missed that it's not to be used on cool-season grasses."

Phelps said Semera can be used on dormant warm-season grasses in states like Arizona and Texas, but is not intended for cool-season grasses, such as Kentucky bluegrass, Poa Annua and Ryegrass, which are used on the City Park golf course. The golf course's rough and greens are unaffected.

Phelps said Semera is often used to kill grass and weeds under trees and along fence lines.

Phelps said it is unknown how much of an impact the herbicide will have on the fairways. He added the herbicide is not a danger to humans or pets.

"It's sort of a waiting game," Phelps said. "The worst case scenario is it is 100% effective and kills all the grass. Or some of the grass may survive. How big of a mortality we have on the grass we don't know yet."

He said the herbicide remains in the soil for eight weeks and that if all the fairway grass is dead, the soonest the course could reseed the fairways is Sept. 1.

"I have had a couple complaints but most people might have assumed we haven't been irrigating," Phelps said.

He said the course will offer $10 off a nine-hole round starting July 5.

If the fairways need to be reseeded, there may be some golf cart restrictions on the fairways due to the heavy watering it takes to get the reseeded grass to grow.

Phelps said he is unsure of the cost of reseeding, additional fertilizer, extra labor and rental of specialized equipment that might be needed to repair the fairways.

"We will take some loss of revenue and with the golf courses being an enterprise entity, we don’t get tax dollars but rely on green fees, so that will affect the golf fund as well," Phelps said.

The city also owns the 18-hole Collindale and Southridge golf courses, which are unaffected.