1/15/2015 6:01 PM
I have had to do a lot of work on moss as the current course had a severe problem on the greens when I arrived 13 years ago.
I have also seen moss on courses all across the country, all budget levels, and on greens with higher heights of cut that putted old dog slow. I have seen moss on greens that looked perfectly healthy and on greens in full sun and dry and firm.
There is probably a combination of several factors working together, most commonly those practices implemented to increase ball roll numbers like lowering fertility and lowering hoc. But other factors contribute too like: topdressing sand selection, infrequent aeration, moisture levels, etc.
In our situation, it is reported, but unconfirmed as there are no records, that before my time they didn't aerate the greens for several years. They had also been using a really fine sand for many years for topdressing to make it easier to brush into the canopy. This resulted in about a +1" layer of fine sand and high organic matter levels over the top of the USGA root zone mix. During that time it was in vogue to use the finer sands for that reason. The result was that the greens would not perc and water would sit on the greens for hours after a rain, even as little as 1/2 inch, if we didn't get the squeegees out. That top layer would also stay saturated for a long time. Their focus had also been speed at all cost and the course had a reputation for having the fastest greens in the Central Indiana area. Fertility levels had been kept low as well as the HOC. All this resulted in many greens that had large sections that had more moss than bentgrass. Other greens were covered in ball mark size moss spots. When the greens would puddle after a rain, moss spores would float and the wind would blow the spores to the edges of the puddles leaving piles of spores after the water would drain.
We began a monthly 1/4" solid tine aeration which immediately helped with the water perc issue and we haven't used roller squeegees since. We also resumed core aeration and filling the holes with the proper sized sand. We have been on a monthly aggressive verticutting program as well to try to get the organic matter under control. This past year we solid deep tined for the first time. All this is helping but chemical controls are still needed.
To begin the moss elimination we tried two chemical controls, Terracyte and Junction. Quicksilver was not yet available. Terracyte worked but as a granular, and the need to nearly blanket every green, it was going to be too labor intensive to apply. Junction, at the time sold by Griffen, was not labeled for moss and their regional rep is our pro's neighbor. We worked on a moss control protocol that ended up nearly wiping out the moss. There is a powerpoint somewhere in the GCSAA archives from a presentation I did as part of the Innovative Supt Session in Atlanta that shows the timing and rates.
We also began adding extra magnesium with our increased fertility program as I read somewhere that low levels could encourage moss.
The problem with Junction is that the high rate needed spiked the copper levels in the root zone mix. We saw no turf health issue but stopped the program after 2 years and about 90% control.
We have been on that Quicksilver program since, 7oz/a, every 2 weeks.
Last year I did get the sprayable Terracyte and applied with a hand sprayer. It worked well but depending on how much moss there is it can be labor intensive.
Chris Thuer, CGCS, Bear Slide Golf Club, Cicero, IN