Hello Peter,

Moss growth in lawns generally indicates that the turf grass is struggling due to poor growing conditions. Conditions are favorable for the moss and it out-competes the lawn grass. Moss can take over if there is too much shade, the soil is poorly drained and damp, there is low soil fertility, the soil pH is too high or too low, the soil is compacted, or there is poor air circulation.

The greatest improvement for turfgrass growing conditions is to open up the tree canopy to get some sun and air circulation into the area. However, since you have moss in the sunny and shady areas, this is not likely what you need. Here is a link that describes good care for lawns: https://www.canr.msu.edu/home_gardening/lawns/index

Here are some references on moss in turfgrass:

https://web.extension.illinois.edu/lawntalk/weeds/solving_moss_problems_in_lawns.cfm

https://hgic.clemson.edu/factsheet/moss-algae-control-in-lawns/

http://ccenassau.org/resources/moss-and-algae-controlling-in-the-lawn

https://archive.lib.msu.edu/DMC/Ag.%20Ext.%202007-Chelsie/PDF/e1516-1986-print2.pdf

A very important step you may want to take is having a soil test performed. This will tell you what your soil pH is and what type of nutrients (fertilizer) are required to sustain a healthy lawn. Details on MSU soil testing can be found at: https://www.canr.msu.edu/news/soil-testing-returns-through-msu-extension Please be advised that the mail delivery has been slow this year and results are therefore taking longer than normal.

If you get your soil tested, please feel free to write back with the results and we can address the remediation procedures for your moss condition.

Hope this helps.