My front lawn has completely died off. After the big snowstorm in January, it started to turn yellow in spots and was very wet. Eventually the entire lawn yellowed and died out except the curb strip. But it too is starting to die out, from the sidewalk side. I dug up a 1-ft square area a month ago to see if there were any grubs and there were none, just a lot of earthworms. The lawn area is in shade until late morning. There is a thin topsoil with heavy clay beneath. I'm wondering if I had (have?) a fungus problem. Would it be worthwhile to have the soil tested, and where would I get that done?
Having just a thin layer of topsoil with heavy clay beneath could be a real problem in establishing and maintaining a lawn. Roots may not penetrate deeply enough to support a healthy turf.
Considering the amount of rain, snow, and cold we had this winter, along with the poor soil conditions, I think this is the more likely cause of your lawn problems.
A laboratory test for organic matter, pH (acidity), and nutrients would be a good start on reviving the area. The laboratory will tell you how to take a sample and provide recommendations on any additions. Soil organic matter at around 5% is ideal.
There are a number of laboratory alternatives in this Extension Service publication: Analytical Laboratories Serving Oregon. Testing should take just a few days. Results can be available on the web, by fax, by email, or by postal mail.
I also recommend a review of two Oregon State Extension publications for an in depth look at getting a great lawn in Washington County: