Reseeding and growing the new grass is up to your care and maintenance. If they are dying off, it's possible you haven't followed the maintenance or they might be the wrong grass for the wrong spot.

Fungus is normal after a tree has been cut, even years later, since they feed on the roots that are decaying off. Sometimes the dead roots will leave a small depression in the ground as they decay, but just level it off with topsoil.

We've tried several times to grow new grass in this spot with different methods and a mixture of grasses. I've grown grass successfully before, so I know how it's done. This is just a big trouble spot since the tree was cut down. I do believe at this point if the seed we put down in the Fall does not come up we will just give up and maybe do some landscape blocks and build it up with soil and try a flower bed or maybe just put a bird feeder there with some mulch. Something to make it look nicer.

How large is the area the grass is dying? This can be common where there are stump grindings decaying under the soil, but not normally through the whole lawn. I could see the grasses used to the shade dying out, but if you reseed with a normal fescue, it should be fine.

The bad spots branch out pretty far and it's not a solid area, it has patches of grass here and there which is why I thought maybe it has something to do with the decaying roots below. It was a very large old maple tree. I figure those roots go out pretty far? Where the trunk of the tree was is the worst part, but then it sort of spreads out from there. Again, not a solid area. There is patches of grass.

I would top dress with some compost and then reseed. The best time to overseed a lawn is in the fall, but it won't hurt to get something started this spring.

Our last attempt was something very expensive that's a mixture of seed and some other matter which helped keep in in place and moist. I'm sorry I don't recall the name. It was great! the grass grew nicely for a little while, then slowly all died. That's why I think it's because of the decaying tree roots beneath. I'm thinking the roots of the grass get down so far and then they get to the bad stuff and it dies/ Maybe I'm wrong, but this is the pattern I see. So...we have aerated and reseeded in the Fall again. Time will tell!