I have had monkey grass (6-7 around some flowers I plant every year (annuals)) in a specific place and every year we would cut it down because, of course, it has gotten much bigger and never had a problem. My neighbor cut them back with his lawn mower this year because they were so out of control (because I am older and cannot spend hours trying to cut them down by hand and my husband always took care of them but passed away last year). They look dead in the middle and overall don't really look good. Do you think I am not watering it enough???
If the center dies out it may be an indication that they need to be divided.
Monkey Grass can also suffer from crown rot fungus.
These links have more information.