Moss Growing in the Sun?

Help!  My velvety green lawn, growing so nicely in the full sun, is now looking sort of sick!

Lawn has a slight yellowish green tinge to it in places.  It gets full sun and regular watering.  What's happening?

Look closer and you'll notice bushy little clumps and strands.

A few strands pulled from that patch of lawn confirm that moss was the culprit.

Why does moss grow in the sun?  Doesn't it normally grow in the shade?

Yes, moss prefers the shade but will flourish in the sun if the soil is too acidic.  Rake out big clumps of moss and apply lime.  (See entry on applying lime.)  When the soil pH is balanced, the moss will die back and the lawn can thrive again.