Propagating existing plants in your garden is the easiest way of expanding your garden. Sometimes, the propagation of plants just happens on its own. When this happens in my garden it is almost as if someone is issuing me a reminder as a reminder that gardening isn't rocket dentistry.
In the fall of 2006 I purchased a perennial sedum for the garden and it was trampled. Instead of picking up the pieces and throwing them I just turned some soil over on them and forgot about the broken pieces of the plant. In April 2007 while doing some spring cleaning in the garden, I happened to unearth one of the stems as I laid on the ground watching some bugs go back and forth through the garden.