I forgot to mention I have also innoculated the area with Milky Spore. No improvement.

Is it brown patch? Very common here. If so, fertilizing actually aggravates it, in that new tender growth is it's favorite thing to attack.

It's a tough one.

Here is a link to read more about it/ see a picture.

Here is a link that might be useful: brown patch info

Here is a link with info plant diagnostic lab on Auburn.

Here is a link that might be useful: Plant diagnostic lab Auburn

Your page doesn't give any indication of where you live, but you might want to call the Master Gardener help line for your area, if there is one. They may be able to furnish you with information and/or put you in touch with the local extension agent. Check the thread linked below for information on calling them.

Sorry. Forgot to paste the link.

Here is a link that might be useful: How to Call Master Gardener Helpline

Hopefully, the Master Gardeners have been schooled into educating you how to scout for soil-borne insects. It's relatively easy to locate the critters, given a few 'tricks-of-the-trade'. You should be able to locate grubs, caterpillars of various kinds, mole crickets (depending upon where you live), and other critters.

By the way, the 'holes' you've been observing could be from the emergence of adult beetles from their 'grub-hood', bird excavation holes (I see that a lot in my yard), among other things.

If the folks at the plant diagnostic lab think that brown patch disease (fairly common in zoysia) is a possibility, they will instruct you as to how to take a helpful sample to send to them for testing. In most instances, lab testing is the only way to determine plant diseases with certainty.

They may suggest that you have a nematode assay done, as well. Nematode problems occur more often than suspected, even here in N. Alabama where I live. These diagnostic tests will be well worth the small investment.

I'll suggest that you stop with treatments of any kind until you get some concrete answers. There's no sense in wasting your valuable time and money on solutions that might be useless.

I came to the same conclusion. Stop messing with the lawn until I'm sure what is wrong. I'll call the master gardener hotline tomorrow. Thanks for that link! It is probably brown patch. The holes are probably due to emerging beetles, I agree. No Japanese beetles yet (crossed fingers) on my roses - Maybe the milky spore is doing its trick on them at least.

Pat,

Just wondering what ever came of contacting the master gardener hotline. My zoysia lawn continues to deteriorate year after year due to brown patch to the point where I'm debating on just starting from scratch.