ordjen, many grasses produce seed heads in the fall. You can just hold off mowing until you see seeds falling from the good grasses, then mow high (thick) to protect them and let them germinate. You can also add seed to overseed if you like, but watch what your grass is doing, it will help you select the best time to overseed.

t_manero, if you suspect that you have a high pH, do not lime. Limestone raises the pH, use gypsum instead. Before you do anything, you should get a soil test first to be sure. If it turns out that you have a high acid soil (low pH), then use limestone, but use straight limestone and apply in the fall and till in.

Another way to combine mulch and decrease a high pH soil is to gather shredded leaves and pine needles this fall. Shredded Oak leaves are the best. If you can find some people around town that have Oak trees and who shred and bag these leaves in the fall, gather up as many bags as you can. Spread up to a two inch layer in the bad spots and till it in, then seed with an annual Rye grass.

In the spring, mow high once, then go over low, preferably with a mulching mower. Do not till the Rye grass. Overseed the Rye with the desired grass and after it germinates, then fertilize with a high nitrogen fertilizer, straight Ammonium Nitrate or Urea Nitrate would be best if you can get it, but don't overdo it.