What to do?

[gobblet]

I have a lawn around 5 acres. 3 acres of the lawn is not doing so well, 1 acre is under a lot of oak trees and the grass has been getting thiner and thiner every year to where grass only needs cut once a month (fertilizer is not doing much anymore) the other 2-3 acres are on the way out also. There is a lot of thatch and really spotted areas of grass. This lawn is over 100 years old and I think it just needs brought back to life.

My quick thoughts were lightly thatching and then aeration and overseeding. It is really to large of an area to bring in fresh soil as I would do on a normal sized yard. This lawn does not have a sprinkler system. How would someone else go about getting some more grass to grow?

[RigglePLC]

Fertilizer will not cure a shade problem--only more sunlight. Perennial rye grass will grow for a few months in shade, if you are lucky. On the remainder, top-quality ryegrass is fine. (Silver Doller is my favorite perennial rye). Consider lawn as rain-irrigated. Try to fertilize with a product high in slow-release nitrogen--apply just before rain or during a rainy period. Try to feed it four times a year--6 weeks apart--ending in late October, but postpone if weather is too dry. Back off if mowing becomes burdensome or too often. If needed, overseed when temps drop below 82, say about late August. Spray weeds as needed in June and September.