Couch Grass – what causes this damage

green couch / bermuda grass (cynodon dactylon) does this in winter, wonder what causes it?












“……..It will be interesting to see the guesses that people come up with, but again I don’t think that there is one definitive correct answer. The most correct answer in my opinion seems to be the chilling injury caused by cold air settlement in the grass (not frost damage). The reason I believe this suits is because the areas where the grass was short the symptoms were non-existent, but where the grass as long and thatchy it was occurring. The cold air was able to be trapped within the canopy of the long grass and cause the chill injury. The chill injury was not caused by frost. I live only 3kms from the site in question and we had experienced no frost prior to this event occurring (in May). Add to that fact that frost damage is usually a blanket type damage not patterned like we see here……….”

This answer was provided by my turf product supplier, Globe Australia, back in 2008.