Hi Rogue,
Thanks for the reply. We live on the eastern side of the Cascades outside a town called La Pine. After the last winter's snowfall and thaw I discovered "grey mold" where we took out some trees and sowed grass seed last year. About a 5 foot square area it was the only spot of mold I found. It was in an area where my husband piled all the snow from the driveway.
We will stop at Wilco, the farm store, in Bend this week when we go into town and pick up the Pyrithrin. And a new Hudson sprayer.