Posted: 13/04/2014 at 11:15
You can get metal edging, but I'm not particularly keen on the look and some of them can be quite expensive (often advertised in the back of GW magazine). Also not so good if children fall over on them. (I was that child )
I prefer to fix a treated timber edge (packs of gravel board from a DIY store will be fine) with hardwood pegs knocked in to hold them to the edge of the lawn, but unless you're handy with the tools it's probably best to get a builder/landscaper person to do it for you.
How to do it shown here http://www.pavingexpert.com/edging2.htm