Brown spots in our yard, we have not found any grubs, any thoughts?

Question

We live in SE Michigan and until just 3-4 weeks ago, we had been receiving so much rain, that we were only watering with our sprinkler system every 3rd day. I have now turned the system to an every other day cycle; we have these brown spots in several places, we have not found any grubs, however, the grass does peel back as others suggest indicating grubs. We have now applied both Grubex and Scotts Step 3 within the past couple of weeks. What do we have and what else should we do? The patches are only in our backyard which is also fairly shaded.

Answer 1

If in the shade, you could have Brown Patch, a fugus which is prevelant at this time of the year when it is hot and humid.

I have put some links to see photos....if this is it treat with a fungicide.

Answer 2

Maybe animal urine, or a high consentration of alkilinity in that area.

Answer 3

Could be rotting from too much moisture and too little sun. You did say that the troubled spots are well shaded. Check with the local nursery for a solution.

Answer 4

Sounds like it could be dog pee, but if you have had a lot of rain you may be over watering and the roots are rotting. Grass lawns should be watered minimally, and never more than 1 inch of water, including rainwater, per week. When grass is heavily watered the roots grow on the surface rather than penetrating down into the dirt where they should be. This makes the grass very susceptible to burning out or to rotting roots.

There may be grubs that you have not seen. Do you have a lot of Japanese beetles where you live? Their grubs will still be pretty small and difficult to find.