After winter lawn damage
I took these photos last May 2nd after our snow melted. We had so many dead patches, our lawn looked terrible and took some time to fill back in. We usually mow the lawn to about 2 inches and usually we put on winterizer (we can’t remember about last fall) we have this problem every year but last year was the worst. Is this damage from a fungus? What can we do to prevent this damage? Also in the third picture the stuff on the left is driveway sand/winter debris not mold.
As a starting point doing a soil analysis would be good. Not only would this tell you if you need to fertilize your grass but will also make recommendations as to the type of fertilizer and necessary amounts. While you could wait until next spring to do this, at that time the University of Minnesota Soil Testing Laboratory will be rather busy and it may be a few weeks before you get results back. It would be more efficient to do this now and then make your necessary spring plans. It is really too late to do any fertilizing now. Take a look at the following. One is a lawn care calendar and the other provides information about soil testing;
I note that your pictures were taken last May. It is not entirely clear to me what your grass looked like at other times during the season. What your turf demonstrated last spring may have been due to mold that developed over the winter and extended into the early spring. The grass damage in the third picture may have resulted from chemicals that applied to the driveway over the winter. If your grass continued to struggle during the summer, other types of lawn fungus could have developed. The best preventative for most fungal diseases is to have a healthy and vigorous turf. To achieve this, I would suggest that you have a lawn service aerate your yard early next spring before extensive grass growth is observed. After this aeration, and if you have the results of your soil test, apply a fertilizer according to the recommendations from this testing.
The first publication of the following three will show what you can do next spring to repair any winter damage. The second and third publication will discuss the various fungal diseases that can occur during the growing season and how to deal with them. In the third publication, note the link at the bottom right of each page that will bring you to the various diseases.
One final point. Several Minnesota yards this past season were damaged by Japanese Beetle grubs. If you observed any of these beetles on your plants during the summer, then grass damage by these grubs would be another possibility. None of the above publications address this issue. If you did experience these beetles last summer, please get back to us as other remedial treatments would then be necessary.