ANNUAL REPOST: The Greens are now "Whites"

Well, it's that time of year again for the Poa annua turf, or po-anna as Johnny Miller would say, has gone to seed!  Our greens turn to "whites" and the rough becomes very wiry no matter how many times a week we cut it.  The prolific seedhead production of Poa annua is something we cannot avoid and must deal with, but remember, although it does affect playing conditions, it also benefits us as many of the millions and millions of seedheads produced end up finding their way into bare spots, divots, ballmarks, etc. to fill voids.  Our neighbours to the south have control products available to them that allow them to inhibit the seedhead production, but there are yet to be any similar products registered for use in Canada.

The timing of the seedhead production is the same each and every year so instead of spending anymore time on this blog entry, I'll share an archived one with you from May 2011.

It's that time of year...the dreaded Poa annua seedhead has arrived!

If you've played recently, I'm sure you've experienced some bumpy ball roll on the greens.  Yes, we are still recovering from aeration, but there is another contributing factor that's creating bumpiness in our greens.  The dreaded Poa annua seedhead!
 

Poa annua seedhead (white seeds) on greens

Poa annua (annual bluegrass) thrives in our wet west coast conditions and is the dominant grass species not only on our greens, but throughout the entire property!  Even at very low mowing heights of .125" (1/8"), Poa annua produces seedhead two times during a growing season, during the spring and fall.  The plant is under a great deal of stress when producing seedhead as it is exerting all of it's energy to do so.  Keeping this in mind, we must be careful not to add too much additional stress with our maintenance practices.

Not only does the seedhead affect ball roll, it also results in messy clumping after mowing in our rough - especially on wet, dewy mornings.  This prolific seedhead production typically lasts 2-3 weeks, but we have observed our species of Poa annua producing seed for 6 weeks and beyond!  Talk about stressed plants!
 

Poa annua seedhead in wet, dewy rough

There are some positives to the seedhead production of Poa annua.  The seedhead finds it's way into bare spots and germinates and matures to fill these voids.  These once bare areas are now much less susceptible to weed invasion.  When properly maintained, Poa annua can provide exceptional putting surfaces.  Some of the top courses in the world have Poa annua greens.  Oakmont Country Club is just one of them and it has hosted 8 US Opens.

Technically classified as a weed, Poa annua does have it's fair share of problems.  It tends to have shallow roots, high disease susceptibility and does not handle temperature related stresses well (heat and cold).

There are control products that suppress the seedhead production; the problem is that they are not registered for use in Canada.  Our neighbours to the south have a huge advantage in maintaining smooth putting surfaces this time of year with the use of these products!  We are keeping our fingers crossed that they will become registered and available in Canada sometime in the near future.  Until this happens, we will continue to work at improving the putting surfaces with our routine cultural practices such as verti-cutting, topdressing, rolling and fertility.  We will also be initiating our plant growth regulator (PGR) program this week.  This PGR program will help to control the different growth rates of our multiple grass species in our greens to provide smoother ball roll.

Here's to hoping this year's seedhead production is a short-lived one!

Why the greens aren't consistently green...

As I'm sure you have all noticed, our greens are sporting a pretty funky appearance this winter.  They are quite "blotchy" and not as consistently green as they have been in the past during this time of year.  The turf growth rates have also been quite inconsistent from one green to another and even within each individual green.

#6 green - March 20, 2014

This is due to a couple environmental factors that are uncommon for our typical west coast winters.  First off, we have experienced some unusually cold stretches of weather this winter where the average daily temperatures were below zero.  For example, in early December we had an 8-day stretch where the average daily temperature was below zero and another 9-day stretch in early February where we experienced the same freezing temperatures.  Our turf can handle below zero temperatures, but they are not accustomed to the lengthy stretches of these freezing temperatures.  

Our greens are most affected by the cold due to their much lower height-of-cut (HOC) when compared to the tees and fairways.  The HOC of our tees and fairways is four times higher than that of our greens.  Some high-traffic turf areas on our greens have "thinned out" a bit and the overall "off-colour" of the greens is a symptom of cold stress.

Secondly, we are actually experiencing abnormally dry conditions this winter.  I know this may be hard to believe with the recent wet weather, but we have had some lengthy droughty periods throughout the past few months that have produced some very low soil moisture levels throughout the course.  As you can see below, there is even some drought stress in some of our rough areas:

Winter drought stress in the right side rough on #18

 

Moisture level readings in the rough this time of year are traditionally between 35% and 50% so needless to say readings such as 14.9% are very low.  The current moisture level readings of our greens are coming in at between 15% and 20% in the "yellowish" less dense areas and between 30% and 40% in the greener lush areas.  Our greens are healthiest when moisture levels are between 20% and 30%.  As you can see, that 10% range when they are healthiest is not a very wide range to work within and can be very difficult to achieve this time of year when we tend to have too much moisture.  

 

Adversely, when we do experience droughty conditions in the winter we can't simply irrigate to reach adequate moisture levels as our irrigation system is winterized and remains shut down until early April.  There is a substantial amount of wet weather in the forecast and before long we will have the irrigation system fired up and ready to go to ensure we can maintain adequate moisture levels.

Overall, the greens are very healthy and their appearance will improve as soil temperatures continue to rise and we move into some more consistent sunny and warmer weather.  The irrigation system will be fired up next week so we will also be able to begin adding supplemental moisture where necessary.  The growth and recovery rates of our turf are still quite low this time of year so patience is key as we can very easily do more harm than good by being too aggressive in attempts to expedite the process.