Mozingo crew declares war on poa grass

The grounds crew at Mozingo Lake is taking a new approach when it comes to maintaining putting surfaces at the city-owned 18-hole course east of Maryville.

Poa annua, commonly known as annual bluegrass, has been creeping onto greens and fairways at courses throughout the Midwest for years, and Mozingo is no exception.

The prolific weed can cause havoc for groundskeepers by diminishing the quality, playability and consistency of bentgrass greens.

Several methods exist for combatting the invasive grass, but none of them is a permanent solution, and some come with undesirable side effects.

This year, Mozingo course manager Ron Darnell and his crew are using a newly approved chemical to designed to eliminate poa annua without hurting existing stands of bentgrass.

The chemical was invented only a few years ago, Darnell said, and was approved by the Environmental Protection Agency this spring.

Darnell and his staff did some research, spoke to salespeople and decided to give the new product a whirl.

Golfers have noticed a difference, but not because the greens are greener and smoother. What they have seen instead are brown spots where the bluegrass has died.

In the city's newsletter this week, Darnell wrote that this had led to rumors that the greens at Mozingo were "going south."

The truth is however, that the brown spots are being reseeded with bentgrass in hopes that the good grass will again take over from the bad grass.

So far, crews have applied the new bluegrass-killing chemical four times, and it seems to be doing the job.

"It most certainly works," Darnell said, "almost too well. The success of the program depends on how fast we can get bentgrass to grow back."

Getting grass to grow in the hottest summer months can be a challenge, but with the course's irrigation system, Darnell believes the bentgrass has a good chance.

"It would be easier if we'd had a good June," Darnell said. "But it was like July and August usually are, and we are coming up to those months."

Weather aside, Darnell is optimistic about the program, and he said the brown spots are, at least, better than poa annua. He also estimates that poa has invaded less than five percent of any given green on the course.

Left unchecked, poa can take over a golf course, a catastrophe Darnell said he has observed first hand.

"This is way better than starting over," he said. "I've seen courses where they had to kill everything on the greens and grow entirely new grass."