I thought this looked interesting.... it's called edg-keeper. I don't
know if anyone here is using it or has tried it.

http://www.olyola.com/edgkeeper.html

I currently am using bolders as edging that is topped with large river
flats and my mulch... I am pretty pleased with the look but I sank
more money into rock than I should have.

Here are some pic's... I need to post some of my new ones... I have
been enjoying the pond in the evening rather than updating my site.

http://members.cox.net/bokowski/