Zoysia grass is probably wonderful, if you live in an area where it is warm year round. By warm, I mean days and nights never below 50 degrees fahrenheit. If the temperature falls, like it does in the great north-east of America, where I live, that thick, rich green, strong grass, starts to turn coco mat-straw beige. If you live in New York State, and have it, expect your infected lawn to be that NOT to LOVELY beige from mid October until almost mid June, when days, and nights again pass the MAGIC 50 degree mark. While it is beige, people will also think you burnt your lawn using too much fertilizer.
Zoysia grass is different from the grasses that make up Eastern lawns, like fescue, blue grass, and perennial rye grass. They all have a root system that grows down into the soil looking for water. Zoysia grass, on the other hand, grows horizontally crawling and creeping more along the top of the soil surface, and choking out any other grass in its path. The root of the zoysia grass is called a stolon, and to me it resembles coarse textured spanish moss.
Somehow, years ago, I got a zoysia grass INVASION in my lawn. I am not sure how, but I think it could have been hiding in the bagged mulch I bought, or in the soil of a perennial, or shrub, that might have been started in a southern state, and shipped north. However it came, I was not familiar with that type of invasive grass, and did nothing about it for a few years. Then all of a sudden, every fall, a BIGGER and BIGGER part of the lawn turned beige, and I knew I had to do something.
My first attempt at eradicating the zoysia grass proved to be worthless, or even helped it to be more invasive. I initially thought kill it with Roundup (a non-selective herbicide)(non-selective means it kills everything it is sprayed on), then rototill the area, and reseed. Thinking that was all it would take to eliminate Zoysia grass was a FANTASY! As I said before, zoysia grass roots (stolon) crawl horizontally. The roots can be 12 to 18 inches long. Growth pops up all along the STRING LIKE root, and it grows our from that string. So in a way, it grows in all different directions. If you don’t get (kill) every inch of that string root, and you go and rototill it, you have just shredded that root into small pieces, and if it is alive, you just made MANY new baby plants.
My second attempt was a success. This is how I did it.
#1..In early spring, when you can see where the beige zoysia grass is, and where your healthy green grass is, take Roundup, and spray a ring around the zoysia grass area, about 12 to 14 inches into the healthy green grass area. Next wait for the zoysia grass area to green up, and let it grow long, so there is a lot of blade surface for the Roundup to lay on. Cut the healthy grass, weekly, as usual, but skip cutting the zoysia.
#2..Wearing safety glasses, a dust mask or respirator, rubber gloves, and protective footwear (every time you spray the Roundup) give the now “long bladed” zoysia a good spraying from a gallon Roundup container, with spray attachment. I had big spots to spray, so I marked off the area into zones, with bamboo garden stakes, that I laid on the ground. I addressed one zone at a time, until all were treated with a good spraying. Three or four days after spraying the Roundup, you will see the zoysia starting to turn beige, and die. After the first application, wait a week or two, and see what you missed, and reapply the Roundup.
#3.. Take your lawn mower, lower the blade, and cut down the dead zoysia close to the ground as possible. You might have to lower the blade a few times to get it down to nothing. Now rake up all the shredded grass.
#4..Start watering the cut down grass area, hopefully encouraging any zoysia root that was not killed by the Roundup to start growing. Do this for a few weeks, to see if anything emerges.
#5..Now the fun part! (Ha Ha)!! With a straight spade or shovel, start digging up the remaining dead zoysia grass and its roots. Wearing a dust mask, and safety glasses, try to knock off as much dirt as possible from the dead grass, and root system of the zoysia. Make sure to pick up any loose roots that you see, and throw them away. Take the discarded sod, and place it ROOT SIDE up, in the sun for one day. That will dry it out. Try banging off any extra dirt again, before throwing the sod away. Bag all the zoysia sod, and root system, and put it in the trash. You don’t want to compost this material.
#6..Now it is time to reseed the spot. Add extra new fill, if needed. For the next year, or two, keep an eye on the old zoysia grass area, and if you see anything beige(ing) up in the fall, eradicate that spot quickly! If you did a good job, the first time, and were careful to kill it all off, and dig it up, you will not have this problem again.
So tell me, would you do all these LABOR INTENSIVE steps to eradicate the zoysia grass, hopefully once, and for all? Have you ever addressed this issue before, and were you successful doing it? I welcome your comments!