Thursday, May 27, 2010

Poa Annua, Taking Over?

Poa annua is the number one talked about grass in America. Courses throughout the country experience Poa invasion at all levels. The Northwest golf courses are nearly all 100% Poa annua including greens. We are currently looking at about 30% contamination on the golf course and less than 1% contamination on the greens.

Poa has been slowly invading the golf course since the construction. Poa is a very efficient annual grass plant. A prolific seeding capability has generated a substantial seed bank over the years since construction. The turf was compromised by disease three and four years ago giving the Poa a great opportunity to germinate with less competition.  This has in turn given us enough of a population to become more noticeable each season.

We have used Trimmit, a plant growth regulator that regulates the Poa plant enough to give a slight advantage to the host turf, the idea being to potentially out compete the vulnerable Poa. We have tried increasing rates of this product, but have only succeeded in making an uneven playing surface in the spring from the patches of Poa being sunken into the surrounding turf. I have not seen the expected regression on the larger patches of Poa. Now, on the greens we are nearly 100% clean. I would have to say Trimmit has some impact on the smaller patches within the creeping bentgrass. We also use hand picking for the small plants in the spring. Trimmit has done a great job on the pinky sized plants on the greens and we have been successful in keeping the bentgrass clean.

The question becomes, what do we do or what can we do now? My opinion on this subject is more of a realistic approach rather than my normal optimistic approach. Depending on how aggressive our membership would like to tackle this issue, we will have continual spread of the Poa. Using chemical control becomes very expensive and results in less than satisfactory results when it comes to complete eradication of the Poa. We can try to manage seed head production in the spring to not get the puffy broccoli looking turf, but we would be kidding ourselves if we thought that we were making a dent in the Poa seed bank that has accumulated over the years. This would be a purely aesthetic approach for a great deal of money.  Growing up in the Poa capital (Pacific North West) and working on relatively new courses I have seen every kind of control exhausted on Poa and I have yet to see one successful in complete eradication. Some have wiped out a lot of grass, but then you are stuck with trying to beat the Poa from germinating and filling in the spots left from the old dead Poa. It is a very difficult task.

Folklore surrounding Poa is that it will die in the summer heat. This is a common misconception. There is no doubt Poa is a little less drought tolerant than other grasses due to the smaller root structure, but in our climate Poa will not die unless something out of the ordinary happens. There is no doubt Poa has a smaller root system then it's competition but it is a pretty resilient plant, it has started to take over in a pretty difficult growing media and is good at out competing the resident turf. Poa isn't as weak or quick to expire as some of the folklore explains.  (Joe Vargas, Proffesor MSU)

What I can say is, Poa control is very expensive and will only prolong the inevitable. Spending valuable resources on Poa may not be the best answer at this time. If you are not getting complete (100%) control on seed head production or simple eradication, Poa will always prevail. Being a logical thinker, I look at the hundreds of thousands if not millions of poa plants growing on the course, if I spend valuable resources to get 80% or even 90% control then we still realize that we have hundreds of thousands of plants still producing millions of seeds that season.

The seed head production will subside later in the spring and the playing surface is not bad at all. Pebble Beach and Cypress Point are both 100% Poa tee to green. I grew up playing and putting on Poa surfaces and the lie you get on a patch of Poa is like placing the ball on a tee. The greens on the other hand we will make adequate efforts to ensure that they stay as clean as possible since Poa patches on putting greens make putting bumpy and inconsistent.

Discussion will continue about Poa. It comes down to playability and presentation, which is more important, how aggressive do we want to get, and do we feel that some type of control is necessary? This issue will become increasingly more noticeable as the years continue..

If you have any questions, please contact me.

Saturday, May 8, 2010

April 2010 Monthly Report

Course Condition

With the weather being cooler than expected this month we are about a week behind on green up and healing from aerification. We even had some snow!

Projects Completed

We have completed the aerification of the Greens. We used ½” quad tines. The USGA recommends that we remove 20% of the surface annually. These tines got us a little over 9%. We are right on track with the Fall aerification planned with larger tines.
The Fairways have also been completed. The tines used were 7/8”. The spacing on the holes is a little farther apart then the greens so we are right around the 9% with our removal.
Recently we installed Barley straw bails in the lakes throughout the golf course. The theory behind the straw is that as they sit in the water they exude a chemical that eliminates algae from growing. Soon, we will spray the existing algae since the bails will not kill algae already surfacing.
Projects in Process

After our fairway aerification was completed, we had many areas that had excess sand. We are working on spraying the sand out of these heavy areas with water. Once the excess sand is removed the affected area recovers quickly. To alleviate this problem for the late summer aerification, we will apply less sand to avoid the build up. We will have some open holes, but we can then come back later and apply another light application to fill the holes and avoid the majority of the sand build up.

We are still working on #13 storm damage on the left side of the hole. We repaired the clogged line and with the heavy winter moisture the area stayed saturated enough to restrict access for our backhoe. Now that the area has dried we are finally putting the project to bed. There was some supplemental drainage that had been installed a few years back that was also clogged and we abandoned the latter section and are going to tie that into our new drainage pipe. This project will be finished shortly.

We have been slowly making our way around the course edging and cleaning out the sprinkler heads and valve boxes, checking pressure at the heads and making any necessary adjustments on the part circle heads.

The weeds in the landscaped areas are also getting sprayed on a daily basis. We are carrying pump sprayers to get weeds as we see them.

Projects Planned

The warmer soil temperatures will be ideal for new seed to germinate and grow. We will target any thin areas in fairways, rough or green surrounds to slice seed a ryegrass/Kentucky bluegrass mix to help these areas move along.

Of course the irrigation system will be a huge part of our jobs this summer as is every summer. We are continually scouting for improperly working heads and heads operating out of specification. The irrigation system is the lifeline for the course. It is important we have everything working properly as quickly as possible.  Read More

Integrated Pest Management

We have controlled for the Billbug adults at around 300 growing degree days. This should reduce the population of reproducing adults and in turn reduce the pressure of larval damage.

This month we are also on the verge of spraying our first preventative application for summer patch. We are monitoring soil temperatures to accurately anticipate pathogen activity.

Read More


There is definitely some Poa out there on the golf course. This year it has become much more noticeable with the wet winter. The Poa has been around since the course has opened. We will continue to have Poa in the Tees, Fairways, Approaches and Rough. The greens, we will take every measure to make sure we do not start to get contamination. Poa may stand out like a sore thumb in the spring but once the seed heads die down in the early summer it will yield a decent playing surface. I think we all know some of the best courses in America are 100% Poa.

Side Notes

I again was invited on the cover of another magazine for the month of May. The magazine is Golf Course Trades Magazine. This article is dear to my heart and it meant a lot to be able to write.  Read article.

Our National Association, GCSAA is sending out the GCSAA TV crew to film The Rim Golf Club and feature the Case Study written last year on our efforts for water conservation. We may also be highlighted on Turfnet TV. This is a national Website with many members throughout the United States. GCSAAtv

If you have any questions, please contact me or Dan.

Justin Ruiz, CGCS                                                                 Dan Devere, CGCS                                            

The Rim Golf Club is a Great Place to Live and Play.

GCSAA TV Video Contest Entry

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