I don't know about anyone else, but I've always struggled to keep dirt and grass out of the pop-up sprinklers in my lawns. Dirt gets washed in and the Santa Anna Couch grass just keeps creeping in, and both clog the mechanism.
In a flash of inspiration this is what I came up with. I had a local concrete cutter make some appropriate size holes in some 300mm square pavers. It cost me $9.00 per hole. I've set the paver into the lawn and raised the sprinkler heads a little so when retracted they are little higher than the paver. Problem solved! No ingress of dirt, and I can trim around the paver with a whipper snipper. They are also obvious enough in the lawn, so that I won't (or Chris won't) hit them with the mower.
