A: The weed grass looks like fescue, which is a common winter lawn invader. BUT….. zoysiagrass is not dormant now. In fact, it does not truly go dormant in winter. Look closely and you’ll see that it still has green tissue at the soil surface.
If you spray a non-selective weedkiller on the fescue, you’ll inevitably get some of it onto the green zoysiagrass crown. That will leave a dead spot in spring…..ripe for further invasion by crabgrass or fescue grass.
My solution? Spray glyphosate (Roundup, etc) on a cotton “wiper” and kill the fescue that way.