My wife and I recently bought a home at which the monkey/mondo grass (sorry, I don't know how to tell the difference between the two, if there is one . . .) has taken over a great deal of the landscape. While a certain amount of this stuff would, I'm sure, create an attractive appearance around our sidewalk and back patio, the sheer volume of it at present makes the entire rear of our new home unattractive to us. There is too much area covered by the plants to dig it all up, and I've tried unsuccessfully to kill it with doses of Roundup, Ortho Weed-B-Gon, and Poast (did I spell that correctly?). While browsing the web looking for a solution to my problem, I came across the PLANTanswers site and saw several questions regarding control of weeds and/or Bermuda grass which had invaded Mondo grass beds. Since there seemed to be a wide variety of things (Roundup and Poast included) which were listed as things that would not harm my unsightly groundcover, I was hoping you might ! be able to direct me to something that WOULD kill it completely. Is there anything you could recommend to me that would allow me to get this stuff under control and create a landscape that would better suit our taste? Our plan, hopefully, is to kill all the ornamental grass then landscape with dwarf shrubs and perennial flowering plants, covering the (hopefully dead) monkey/Mondo grass with a single-shredded hardwood bark mulch.
Monkey grass and mondo are the same (Ophiopogon japonica). Perhaps you could place a sign at the curb or an ad in your local paper saying that you had monkey grass free for the taking (digging) and see if you got takers. There are always others who would like to have your plants as long as they are free.
I think that if you wish to eradicate the monkey grass you could do so using a glyphosate product such as Roundup. I would probably wait until next spring and then first mow the plants as low as you can. Allow the plants to begin new growth and after it gets about 2 inches high, spray it with a maximum recommended strength mixture of the Roundup (at least two and one-half percent). If you buy the most concentrated strength available (41 percent), which is the most economical way to go, this would be about 4 tablespoons per gallon. It may take more than one application, but this should kill the mondo. Also there is a new nut grass herbicide that is sold under the trade name "Manage" which I have used to eradicate nut grass (nutsedge). It also killed the mondo when it was used there.