Can you post a picture of your mondo grass? Please tell us a little more about it. Perhaps one of these articles might be helpful.
Are you growing it as a groundcover? If so, once it's established it can pretty much be ignored. But to get it established requires a little bit of care. See the following article.
https://www.gardeningknowhow.c...
Are you by chance growing mondo grass as an indoor plant? If so, here's a link that might be helpful.
https://www.thespruce.com/grow...
