Explaining 'Poa Annua' on Golf Courses

A poa annua putting green at Pebble Beach during the 2010 US Open
A splotchy appearance, as on this Pebble Beach green during the 2010 US Open, is a possibility with poa annua grasses. Stephen Dunn/Getty Images

Poa annua is a type of grass sometimes found on golf courses and sometimes used as the putting green grass. The best-known example of poa annua's use as a turfgrass in golf is its use as the putting green grass at Pebble Beach Golf Links. Poa annua can be used on other parts of the course, too, and is sometimes the grass of choice for rough.

If you watch a golf tournament on TV that is broadcast from a golf course where poa annua is used, you'll hear the announcers frequently refer to it simply as "poa" as a shorthand.

The Poa Family

Poa is a genus of bluegrasses. There are approximately 500 species of poa, which, collectively, are called "poagrasses."

According to the Golf Course Superintendents Association of America:

"... poa pratensis is the species name for Kentucky bluegrass. Poa annua is annual bluegrass. There's also Poa trivialis (rough bluegrass) and Poa compressa (Canada bluegrass)."

Poa annua is easily the one best-known to golfers, primarily because of its use as the putting surfaces at Pebble Beach.

Poa annua is a "warm-season grass," meaning it is a grass that grows better and healthier in warmer climates.

The Golf Characteristics of Poa Annua

Poa annua can create a distinctive look on golf course putting greens, and it also has a characteristic that can actually impact how golfers putt such greens.

Splotchy Appearances

Putting greens that use poa annua can have a splotchy or streaky appearance to them, because of the many different strains of poa annua.

The more different strains there are in a particular putting surface, the splotchier or streakier that putting green may appear.

This is often just a cosmetic affect that does not impact the quality of the putting surface in terms of smoothness. But it can affect the smoothness of the putting surface.

Depending on the strains involved, this mixture of strains can lead to bumpiness or patchiness.

Needless to say, golf courses that use poa annua pay close attention and try to control which strains are growing on those greens. Controlling or "resisting" the incursion of new strains of poa annua - or any strains of poa annua, if your golf course does not use it as one of its turfgrasses of choice - is something course superintendents spend time on.

Fast Grower

Poa annua has another quality that some golfers don't appreciate. That quality is this: Different strains of poa annua can grow at different rates during the sunny part of each day. And poa is a very fast-growing grass, particularly when compared with many other types of golf course turfgrasses.

What does this mean? It means that poa annua, soaking in sunlight, grows to a noticeable degree during the course of a golf tournament day. Which is to say, golfers who play on poa annua greens in the early morning and golfers who play on them in the late afternoon may encounter subtly different putting properties.

That means that in the late afternoon, after a day of growing time, a poa annua green might be less smooth - bumpier - than it was throughout most of the day.

This characteristic of poa annua - its fast growing time, which can very subtly (but noticeably) change putting conditions over the course of a day - makes it unpopular with some golfers. Tiger Woods is the most famous detractor of poa annua greens. While he has never publicly stated it as a reason, it is widely believed that Woods stopped playing the AT&T Pebble Beach Pro-Am tournament on the PGA Tour early in his career because of his dislike of Pebble Beach's poa greens.

You can find much more information about poa annua use on golf courses by conducting a search on USGA.org or GCSAA.org.

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