Q.Why does my Zoysia grass have so much weeds now? And how do I get rid of it?
My lawn of over 20 years consisted of Zoysia grass. For the most part, the grass is weed free. I get some (not much) weeds in early spring, I pull them out and my lawn remains weed free for the rest of the season. Never having to use any weed killer.
However, that is not the case this year. My grass had the usual amount of weeds this
spring. I pulled them out. In the last 2-3 weeks, my lawn is not inundated with all kinds of weeds! I live in Illinois, and we’ve had a lot of rain and unusually cool temperatures. I’m assuming that’s that the reason for all the weeds. Is that correct? And, WHY??? What’s the reason for that? Trying to get a professional landscaper to treat the weeds; but not having too much success at the moment. Can you suggest a good weed killer for Zoysia grass? Do I need to aerate my lawn again?
Any information and suggestion would be greatly appreciated. Thank You.

Certified GKH Gardening Expert
Your lawn must have thinned out some in order for so many weeds to sprout. By keeping a think mat of grass through proper fertilization, mowing and irrigation, most weeds cannot grow. Weed seeds lay dormant in the ground just waiting to be disturbed. Weed seeds also blow in from the neighbors' yards. Aerating your lawn may have disturbed enough weeds, then plenty of rain fell. Most yards have a small percentage of weeds that are overlooked. But if the percentage tips in the weeds' favor, you may need to look at some chemical control to get it back on track.
No till gardens are becoming popular as a way to deter weeds. The tilling brings up all those dormant weeds and gives them the opportunity to grow.
https://www.gardeningknowhow.com/plant-problems/weeds/pre-emergent-herbicides.htm
https://www.gardeningknowhow.com/plant-problems/weeds/post-emergent-herbicides.htm