This has truly been a very interesting year weather wise and I am starting to see a increase in the Poa Annua population on the golf course. Poa Annua or Annual Bluegrass is a weed here at Hawks on some golf course it is not. Some of you may know a little about this grass if you have been involved in other clubs in our area. I would say that most older clubs have a very high percentage of this grass on their courses be it on the greens tees or the fairways. This grass can produce very fine playing conditions, because it can tolerate many different heights of cut and is a very dense grass. The problem is that it is not a very strong grass, it has many disease problems and in the winter can die do to the extreme winter weather patterns that we have here. Over the last few winters many clubs have had serious problems in the spring mainly because of this grass. There are a few positives but not many. This year has been fairly mild temperature wise and this gives the Poa Annua a excellent opportunity to grow the bentgrass usally has the competitive edge in the summer filling in any voids from any dead Poa Annua but this year it is the opposite. Bottom line there has been a noticeable increase in the Poa annua population here. There are a few things that I do to give the bentgrass the competitive edge some examples are keeping the soil fairly dry to encourage the bentgrass, using foliar fertilizers and limiting the use of Nitrogen, and using growth regulators. I will focus on growth regulators at this time
Growth regulators are chemicals that we use to slow the top growth while encouraging rooting and stress tolerance. This is interesting because one of the growth regulators can increase the stress tolerance of the Poa Annua also. Problem is this is one growth regulator that does work very well for summertime use and has no real side effects on other types of turf. This is important to note because normally the summer is somewhat stressful and slowing the growth of plants can also have negative effects that may not be desirable. This year I started to work with a new type of growth regulator that does work very well on the bentgrass but has some negative effects on the Poa Annua. Last week I applied this growth regulator to the tees and the fairways were also sprayed 3 weeks ago. What I am looking for is the Poa Annua to become stressed to the point that the bentgrass will fill in over top. You may start seeing this happening while you play. There may be some discoloration of the Poa Annua this should be considered a good thing and with my fingers crossed we may see a nice transition back to the bentgrass.