I have stone around half of my pond, in clay without a liner. The sloop is not steep, so there is no problem with sliding. They have been in place for 9 years, and still look good. I need to refresh some areas with additional stone, where they have started to bury themselves. Three or four times each warm season I spray Touchdown Pro (an aquatic form of Roundup)on the rocks to keep most weeds at bay.
