we just moved in last September but have noticed bad drainage a lot of moss and a few bumps and hollows as well as a few bare patches on the grass. It is at the back out of site however i still want to make it as good as possible the moss i was going to treat with moss killer the bumps i was going to dig up and restore but what about the hollows if i put compost on top of the grass will the grass come through or how should i treat my grass any suggestions appreciated thank you