Dear Member,

We are embarking today on the control the “silvery-thread moss” (Bryum argenteum) that is present on certain greens. The products used to control moss are few and quite risky to apply for grass in-season when temperatures are high. Now that the temperatures have reduced, but there is still good grass growth, it’s the perfect time to knock the moss off.

When the moss die’s back, it takes circa four weeks to replace via natural grass regeneration and over-seeding. While this is happening, the greens can become bumpy and so for this and other reasons we elect to do it with the autumn course maintenance work at the end of competition season. You will see the moss turns from green to black and become very evident until the new and existing grasses grow through it.

The attached photo shows an area we treated four days ago on our turf nursery. Colour change from green to black has occurred indicating the moss is dying. The grass that was being swamped by moss can now emerge and recover. For areas of very heavy infestation, the moss will be plugged out and replaced with greens’ grass yielding an immediate repair.

I thought I’d also include the explanatory paragraph I posted previously below so you can better understand why we have moss:

“This type of moss is becoming more of an issue for golf courses across the globe and current thinking is this is due to: lower mowing heights to achieve higher green speed, the removal of pesticides that prevent it, as well as other less significant cultural factors like: excessive thatch, poor light quality, poor drainage, and others that we don’t suffer from. In our case, it’s a temporary transitional problem as the thinner Creeping Bentgrass declines – because of unsuitable climatic conditions and winter wear – creating gaps in the surface that are then quickly populated by moss; before eventually being replaced by invading Poa-annua.”

The good news is that the amount of moss declines as the higher density Poa-annua takes over and stops the gaps from forming where moss can invade. So, Garden has the least amount of bent and therefore moss, whereas Mill the most of both, and church somewhere in between all due to their relative ages since re-turfing with bent in 2008, 2011 & 2013 respectively.

I trust this helps you to understand the moss situation better and reassures you that it is only a temporary stage in the development of our greens from Creeping bent to Poa-annua.

John Lockyer
Director of Greens