Q.What Causes Moss In The Lawn And How To Get Rid Of It. Where To Dispose It
my lawn is about 30 years old, there trees shading some of the lawn. large oak tree- no moss there weeping cherry tree- ground under it is covered with moss it started about 2 years ago and now covers the ground under the tree

Certified GKH Gardening Expert
This process can be quite long and drawn-out! The best way still takes quite awhile, as you must remove the environment in which they thrive. The best way will be to have a professional take care of it. You can contact your local extension service for help finding someone near you.
This link will help:
https://www.gardeningknowhow.com/extension-search
Should you choose to take on the task, these articles will help: https://www.gardeningknowhow.com/home-and-garden-reviews/get-rid-of-moss-in-lawn.htm
https://www.gardeningknowhow.com/ornamental/foliage/moss/killing-moss.htm