Is it Zoysia and Should I Kill it?

Question

Back in 1992, we moved into this new home and the yard was a complete weed patch and the builder only seeded a small area extending out from the house. The other 1+ acre was weeds and some grass. I killed the entire 1.2 acres with Vantage and Round Up and re-seeded with a mixture various Tall Fescues ending up today with pic5. Since then I have kept 95% of the weeds out and have applied crab grass and grub control and fertilized twice a year. I have noticed what I think is Zoysia spreading in various areas. I first noticed it a few yrs back. For instance, grass10 is up front by the driveway. Grass11 is across the other side of driveway about 100 feet away near a tree. The largest ares is seen in pics grass 7,8,9. I am not sure if it is Zoysia. If it I, I don’t know how it got in my lawn and how it shows up in different areas.

I am wondering if it makes sense to kill it off since I spent the time getting my lawn in shape and maintain it or let it go? I assume it would spread more? I was thinking of killing the front by the driveway, grass10 and some of the larger area like grass9 and a bit each year as it is costly and time consuming to do many areas at once. I also have to prepare seed and area after a tree is taken out that is about 15 feet in diameter.

Answer 1

Stan, Only one photo came through, it appears to be normal fescue turf, but hard to determine species from the photo. There are no obvious patches of invasives.
Your primary question is – should you take steps to control invasive zoysia? Of course it depends on your tolerance for the mixture of grasses and the invasive nature of zoysia, and on your time and budget for eradication and replanting. The fact is that zoysia will take over and if you have put that much into creating a uniform fescue turf, you may want to go the distance and get the fescue out before it takes over. Unfortunately there is no selective herbicide that I know of for killing the zoysia and leaving the fescue unharmed.

https://www.kansascity.com/living/liv-columns-blogs/kc-gardens/article30984585.html

https://www.gardeningknowhow.com/lawn-care/specific/zoysia/facts-about-zoysia-grass-zoysia-grass-problems.htm