Posted: 07/03/2012 at 12:18
I have the same problem & agree with what has been said. Moss likes shady, damp conditions & poor drainage. Try this - Apply Sulphate of Iron 4oz sq. yard to the moss area. After a short time the moss will turn black & die. Throughily scarify the area till no moss remains. Dig aeration holes with a fork lifting up the sod will do no harm (trust me) although initially it will look awful. Apply a mixture of compost & sharp sand (not builders sand) 50/50 to the area. Resow with a shade tolerate grass seed.
Note! Apply Sulphate of Iron periodically throughout the year.
For a more radical approach try relaying area with a broad leaf meadow turf or even couch grass. Both of which seem to grow fairly well under trees.