I live in Portland and I moved into a house in 2016 that was built in 2012. The previous owners had two large dogs that really left some large bare spots in the lawn. I have been working hard to get it into shape. I try to weed and feed the lawn twice a year. I also over seed the bare spots in the early Fall and it worked well. Over last winter, I noticed the many areas of the lawn started to thin out and moss developed. I used a product to get rid of the moss in the spring of this year and it worked pretty well. I was wondering if having moss was an indicator of having acidic soil? Should I lime my lawn? I do not have a soil pH device.
Soil in western Oregon is acidic, and often lime is used to adjust the pH for turf. It isn’t, however, always required, nor does it fix moss. Moss growth is a function of sun/shade, drainage, health of the lawn, and the simple fact that our winter environment favors moss over grass. Basically, you need to take good care of your lawn and plan to regularly reseed if you are in too much shade (or choose a non-lawn landscape). Here are publications about moss, lawn care, and lawn replacements. There really are many specifics and situations to consider.