I think if you were to take an informal survey, you’d be hard-pressed to find a single golfer who likes or even prefers to putt on Poa annua greens. And no, it’s not Poana. It’s Poa annua. For my money, the best greens in the world are bentgrass greens. Augusta National agrees. All of their greens are bentgrass. Good bentgrass is like putting on carpet.
In Principles of Golf Course Maintenance with PGA Professional Gary Balliet, one of my classmates laid out a pretty compelling case that Poa annua doesn’t even belong in the “grass” category. He argued that it’s a weed, but then again, pretty much any grass you don’t want growing could be considered a weed.
On certain courses in certain parts of the country, Poa annua is unavoidable, and what makes it such an insidious strain is that it’s one of only a few grasses that will survive on tight, compacted soils.
According to Practical Golf Course Maintenance by Gordon Witteveen and Michael Bavier, “There was an unexpected and beneficial side effect of cutting fairways with riding triplex greens mowers and removing the clippings. Superintendents in northern regions who had been struggling with poa annua infestation in their bentgrass turf noticed that the bentgrass thrived once the switch was made to lightweight mowers.”
Witteveen and Bavier continue, “After only a single season of regular cutting with the riding greens mowers, bentgrass could be seen spreading and outgrowing the Poa annua. Since the use of lightweight mowers, bentgrass has been able to outperform the Poa annua. Lightweight mowers cause less compaction than the heavy tractors of years past.”
Lightweight mowers mean less compaction, and less compaction means other grasses, like bent, can now thrive. Here is an excerpt from today’s PowerPoint presentation. Where appropriate, names have been redacted to protect the innocent:
What is Poa annua?
Poa annua, or Annual Bluegrass as it’s sometimes referred to, is an annual weed that looks similar to regular lawn grass for a short time. It has shallow roots and develops a short seed head early in the season.
Poa annua is Good
There are two schools of thought on Poa annua. The bottom line is that for many courses, it’s simply unavoidable. Of America’s 100 Greatest Golf Courses (2015-2016) according to Golf Digest, seven of the Top 10 courses have Poa annua greens.
1. Pine Valley Golf Club – Pine Valley, New Jersey
3. Cypress Point Club – Pebble Beach, California
4. Shinnecock Hills Golf Club – Southampton, New York
6. Oakmont Country Club – Oakmont, Pennsylvania
7. Pebble Beach Golf Links – Pebble Beach, California
9. Winged Foot Golf Club – Mamaroneck, New York
10. Fishers Island Club – Fishers Island, New York
Poa Annua is Bad
Poa annua is nearly impossible to get rid of. Golf course superintendents have spent thousands of dollars on herbicides trying to kill it. Gary Lindeblad is the former Head Professional at Indian Canyon Golf Course in Spokane, Washington. Lindeblad compared Poa annua to cancer. Golfer’s at this year’s U.S. Open at Chambers Bay blamed missed putts on infestations of Poa annua into the already sparse fescue greens.
Poa annua is an invasive grass species that thrives in cool, moist climates and germinates quickly, which allows it to spread. “It’s the strongest, most enduring plant there is on the golf course,” says Lindeblad. “It’s like fighting with your wife. You think you’ve won, but you haven’t.”
You could argue that Poa annua greens are great in the morning after they’re first mowed, but as the day progresses and the seed head grows, the putting surface gets a lot bumpier and putts get knocked offline.
The Verdict is Still Out…
Mention Poa annua to superintendents, and you’ll get vastly different opinions. In the South and Mid-South, superintendents protecting their Bermuda grass fairways and greens despise it.
Those in the United States’ transitional zones and northern tier who have bentgrass greens learn to control and live with it, while others in the northwestern corridor care lovingly for their 100-percent Poa annua putting surfaces.