Maybe Poa Annua Isn’t So Bad?

The U.S. Open is being played at Pebble Beach this week. One of my favorite things is when the pros play Pebble because the announcers talk extensively about Poa Annua or Annual Bluegrass. Annual Bluegrass greens get a bad rap for several reasons. They are more difficult to care for because they are more susceptible to certain diseases and insects. Proper irrigation is more difficult because of a genetically restricted root system. The plants produce profuse seed-heads in the spring creating poor putting conditions. They are more susceptible to winter damage. I could go on and on.

Why do so many golf courses continue to manage Poa? Number one, it’s very expensive and requires a lengthy course shutdown to convert to creeping bentgrass. Number two, with proper management, Poa greens can provide an outstanding putting surface for the entire season. Golf course maintenance has come a long way in the last twenty years. There are many more “tools” at our disposal to manipulate this grass species.

Our greens are between 80% and 90% Poa Annua. While watching the tournament this weekend, you’ll notice the mottled, blotchy look of Pebble Beach’s greens. Our greens look the same. The different colored blotches you see are mostly the different strains of Poa.

Although labeled an annual, there are hundreds of strains of perennial Poas. Different varieties will survive best in their genetically determined environments. A Poa grass plant that has grown in shade for many years will likely be a different variety than a plant that has grown in the sun. In truth, there can be many varieties on one green alone. This leads me to another issue about Poa Annua. With many varieties come different growth rates and styles (upright, prostrate, etc.). This means that late in the day some plants may have grown more than others creating more bumpy conditions. I guarantee you will hear all about it this weekend when a player misses a putt late in the day in one of the rounds. Someone will blame the Poa for the missed putt.

This weekend’s player interviews and host commentaries should provide an abundance of information on Poa Annua. Take it all with a grain of salt. Last time I checked, we’re watching the U.S. Open at a venue with Poa greens. Heck, Oakmont Country Club’s Poa Annua strains are so rare that universities are trying to breed them. If I’m not mistaken, Oakmont has also hosted a few majors.