Aha. Last Sunday, I was just talking with my friend who is a
botanist at our local university. She and her husband conducted
an experiment on their own lawn to evaluate moss-control methods.

Suggested strategy as a result:

1. rake as much of the moss out of the lawn as you can. You can
put it into the compost.
2. cut the grass long, not short
3. apply lime and fertilizer in modest amounts

"Moss killer" fertilizer containing ferrous sulfate may help but
raking the moss out is (as written above) the #1 thing to do.


That is a years old standard treatment

Surely that doesn't mean that the news that someone has tested it
(presumably against a control or other possible methods), and proved
it
to work, isn't a good thing.

My friend and her husband are both research botanists and have a
distinctly scientific and experimental outlook on such matters.

As Victoria Clare has guessed, they conducted a simple but
reliable 2-way experiment, so the recommendation is, for a
pleasant change, not based on old wives' tales.


Not all old wives tales should be belittled, indeed your friends have
just proved that a long established (because of its effectiveness)
highly potent method of treating moss is validated. I did not try to
denigrate your friends I merely said it was a long established method.
See also my reply to Victoria Clare.